I really like the Lance composition options in this game, especially in multiplayer where you can set a limit to the value of your lance and must balance it out accordingly. I tend to play in the 25M bracket using 1 heavy, 2 mediums, and 1 light. A lot of people push for a team of all heavies and mediums, though I find that the limit prevents you from equipping them optimally and I usually win those matchups even though I'm using a lance of smaller chassis'.
My current favorite lance setup is
- Firestarter - this little thing is versatile as hell, although I stripped the M lasers off it. He basically works as a sensor-lock machine hovering on the edge of the fight until he can jump in and set things on fire.
- Grasshopper - My main attack, I filled this thing with 6 flamers and 6 M lasers (which work well at the same range as the flamers, so if you get in close you can do some serious damage). It's only a heavy, but it can go toe to toe with plenty of assault mechs. Probably my favorite of all the mechs out there.
- Centurion x2 - I have a pair of these badboys filled with 30 LRM's and their job is to sit on the edge of the field with bulwark and plaster anything that moves. As they're medium mechs they have more initiative than most other heavy support mechs while still having better armour, and you can even stick jump jets on them without sacrificing too much.
It's a pretty weird lance in that I have two very aggressive mechs and two very defensive ones, but I find that if I can get the evasion of a heavy/assault down then because of the range of those LRM's I can get 60 LRM hits which is pretty much a guaranteed knockdown on anything. Once it's knocked down I can set it on fire and then it's just fucked.
I tried playing around with some alternatives to the Centurions but couldn't settle on anything I liked. I put a Kintaro in there for a while, as they can mount 40 LRM's instead of 30, but I found the heat management and less armour you got as a result wasn't worth the tradeoff. I also looked at a catapult build but I don't want my main close-range attack to be anything less than a heavy.
I feel like there's a very similar deck-building dynamic to a lot of the card games out there like hearthstone, so I'd be interested to know what other people are using.