Tactics 101 was the basics and concepts of fighting. Tactics 201 is the stuff you can actually use.
In Tactics 101, you were taught the basic concepts and maneuvers that are taught to the fledgling US military officers on how to make war.
Let's talk about real world applications. These are presented in no preferential order. They are all equally important.
Unit Types
There are six basic groups of ‘Mechs: Scout, Missile Boat, Sniper, Skirmisher, Juggernaut and Brawler. In an ideally constituted “take on all comers” force, you will have all six unit types covered. In reality, mission parameters may cause for some types to be doubled up on and some types left out.
Scout: Lightly armed and fast. It depends on high movement modifiers just as much as it’s armor to survive. Good for spotting, indirect fire spotting, and hit and run attacks to the back or flanks. Does not last long when the bullets start flying towards them.
Missile Boats: These are the “screw everything in that ZIP code” guys. Imagine a lance of Longbow -12C’s who can put 660 LRM’s down range a turn. Their weakness is the bubble under seven hexes where their LRM’s are basically useless.
Sniper: High damage per shot at long range. Arrow IV’s, Gauss Rifles, PPC’s and other weapons who can hurt you from 15+ hexes away.
Skirmisher: A conglomeration of Scout, Sniper and Brawler. Speed like a Scout to move and keep at mid-range where their weapons shine, Able to deal good damage in their range bracket like a Sniper and the ability to get up close and personal like a Brawler. Falls victim to the “the more things it does, the less well it does in all of them.” Good general unit that excels at nothing but can fill in a hole in a pinch.
Juggernaut: Unstoppable advancement, no matter how much you throw at him. If you need to do a frontal assault on a fixed position, these guys fill the bill.
Brawler: Up close and personal. Marked by a majority of medium- and short-ranged weapons, these guys are buzzsaws at or near base contact.
These types work together and against each other like “Rock-Paper-Scissors-Lizard-Spock.” If a Brawler can get under the minimum LRM range of a Missile Boat, that boat will sink. A Juggernaut will grind to a halt in the face of a couple Missile Boats and/or Snipers and so on.
Give them no good choice
On Star Trek:TOS The Savage Curtain (Season 3, Episode 22), Abraham Lincoln tells Captain Kirk, "You should give your enemy what he wants. Just not the way he wants it." You always want to give your opponent choices. That being said, you want to give them choices they don't want to make. Make them choose between horrible and catastrophic. If your opponent wants to overrun your infantry with his tanks, make sure his choice is to either run his tanks through yours (thereby losing a large number of them) or avoid your tanks and run his tanks through a minefield. Either way, his tanks will be a weakened force and easily swarmed by the infantry by the time they reach your infantry.
Mutual Support
Each unit of your force needs to be close enough to the rest so if one gets in trouble, the other units can assist by offering more targets, beating more on one of the opponents units, etc. While you don't need to be one hex away from each other (this would be very bad if area effect weapons were in play, like artillery, Arrow IV's, air support with bombs, etc.) keeping the range under five hexes to at least two friendly units is a good idea. Keeping your forces in a circular or semi-circular formation will minimize flank attacks. A long single line invites flank attacks where your firepower is at its weakest. Think Infantry square.
Cover and Concealment
While similar in their use, these are realistically two different things.
Cover is hiding behind a solid wall. Your opponent cannot see you, nor can he shoot through the cover to hit you.
Concealment is hiding behind curtains. They can't see you like when you’re in Cover, but if they correctly guess where you are, the incoming fire is not blocked and you will be hit.
In BattleTech, Concealment is standing in a light or heavy woods hex or moving at least 7 hexes a turn. Your opponent can hit you, however the actual chance of doing so will be very small at medium or long range. Cover is standing in a heavy woods hex, surrounded by light woods (or more heavy woods). This means you can't be shot, however if you positioned yourself correctly, you can shoot your opponent.
Maneuver or Fire (Leapfrogging)
In over the vast majority of land-based combat games I have played, you have no penalty and sometimes a bonus if you remained stationary to fire, however if you shot while moving, the shooting was at an "unfriendly modifier." How is this solved? By only advancing half your force at a time. Some of your units would remain stationary in a given turn, maximizing their firepower (ideally from cover or concealment), while the other units moved into the position they want to be in next turn to maximize their firepower and allow the stationary units of last turn to advance and keep up.
The advancing units are in no way restricted from firing, just remember they will have a penalty in their shooting.
Focused fire
In BattleTech, it is a natural inclination for units to go mano-a-mano or duel one-on-one. A subset of this is to try and pair your heavier units with his lighter units to have a good chance to beat them down without taking too much damage. The bad news is, a lucky hit or two can drop a 'Mech very quickly.
This answer to this is focused fire. This means that everyone pour their fire onto one exclusive target until it is destroyed or rendered ineffective. The total firepower of an entire Lance or Star upon one hapless target will eliminate the target in a turn or two. Mind you, you have to pick an appropriate target based on your level of firepower. A Lance of Locusts will have a devil of a time taking out an Atlas, I am talking more about a Lance of heavy/assault 'Mechs on a medium unit.
I beat the crap out of and killed a Thunder by pouring fire from a Bushwacker, Battlemaster, Marauder and a Mauler onto him for two turns until I wiped out a side torso and his XL engine.
Crucible
A crucible is a container meant to hold very hot things, like molten metal. In this context it means "a severe, searching test or trial." The Crucible tactic is actually the inverse of Focused Fire. This is where you intentionally offer one of your units to be the primary target of your opponents' fire. Ideally it can withstand the damage. The secret here is... don't keep them in the crucible too long. A given heavy or assault 'Mech can take it for no more than 1-2 turns before the damage starts to get severe and it has to get out of the way and let the next 'Mech take its’ place.
The main idea here is by offering one of your units as a juicy prize, you will (hopefully) draw his units into a position where you can focus fire to take one (or more) of his units out.
Isolating One from the Herd
When a pride of lions attack a herd of water buffalo, the lions never try a maximum force frontal assault. The horns and hoofs of a herd of buffalo will always beat a lion. What the pride does is coordinate their actions. One lion will creep into position and jump up to surprise the herd and spook them into running past the rest of the pride. The pride will locate a slow buffalo at the back of the herd (baby or old), then isolate them from the protection of the herd and take the single target down easily. Dinner is served.
In BattleTech, this translates to using Cover to shield all of your units from all but one unit of the opponents' force. I did this during a battle. I was facing a force centered around an Omega (150 ton ’Mech) who had a “mini-me” (Urbanmech) trailing behind. I moved a Shadow Hawk so he had LOS (line-of-sight) to the Urbie, but not the Omega. This isolated the Urbie from the support of the rest of his buddies and I proceeded to kill it.
Defeat in Detail
I mean his defeat, not yours. This is actually a strategic-level tactic (theatre-wide) but this also works on the tactical (squad level) as well. Defeat in Detail is great when you are facing a superior force. You (as the smaller force, say 10,000 points) separate or appear to separate your force into say four small groups of 2,500 points each. If your opponent (who has 25,000 points) does this as well to engage all of your forces simultaneously, they now have four forces of about 6,000-7,000 points each. If you have superior mobility, you can reunite your force back into the one large 10,000 point group, which can easily defeat the opponents smaller groups.
On the BattleTech battlefield, if you see your opponent divide his forces into 2-3 groups, advance leapfrogging at one group (or remain stationary in cover and let him come to you), then using focused fire engage it until it is eliminated. Once that is done, move on to the next group.
Hammer and Anvil
This is sort-of like a turning maneuver from Tactics 101, however the execution is a little more difficult. And more devastating.
Force A (your Anvil) remains somewhat stationary, in cover/concealment with an open killing field in front of them. Force B (Hammer) then proceeds to chase your opponents force into the guns of your Anvil. This is what happened to me in A Wild Hair batrep.
A Way Out
A final note, always leave a path for your opponent to retreat. Forces fight harder when they are cornered with no retreat. They are easier to break (morale wise, the models on the board and between your opponent's ears) if they think they can escape. Let them find out after they get in there that you pre-mined it....
Let me know if any of these helped you out in your battles. I also accept (and credit you) other battlefield tactics.