One thing the Marian Hegemony has figured out, it's conventional infantry. Deploying a full company wherever anyone else would deploy a single platoon will do that. When I first got back into Battletech, I was thinking about doing my stuff up as Marians, but the other limitations of such a minor power meant I went with Capellans in the end.
Alpha Strike seems to have more of a wider picture of warfare than TW does, with lighter mechs and more conventional elements and vehicles performing better than their TW counterparts, so perhaps a Marian Hegemony combined arms force would be quite hard to deal with.