That's pretty much what he means by escort. It's common sense in larger games, but in a lance-sized fight you probably want more well-rounded machines, since an escort that didn't have any enemies close with its charge is 20-25% of your force doing very little to contribute to the fight. Even SRM Carriers aren't cheap enough for it to be acceptable for one to sit idle in a small-unit fight.
Yeah there is fallacy of division and composition. The larger the scale of battle, the more specialists win the war. Especially since in such a situation, redundancy matters ( "Oh you took out my Command Mech, well I only have three more left. " ) also because such wars acquire a more Industrial quality. I mean yeah, if I only have four Mechs, and I have no idea of what I am facing for an extended mission, I might want generalists more as the Lance Commander. Heck, I might want that anyways, Grand Strategy be darned.
Also circumstances matter. If it is a long-term mission where you fight a lot of medium vees and infantry, you might not want a King Crab due to limited ammunition. Heck if it is urban combat, you might not want Field Units at all.
