I disagree, Catapults ARE brawlers if you put enough SRMs in them and Assault mechs ARE magical girls if you put enough tutus on them!
Seriously I'm usually a little scared of Catapults full of SRMs, that alpha strike damage is usually enough to fuck you up, sure you'll probably kill the Catapult after but any friends it had are going to absolutely ruin you, and if they do that before you kill the Catapult then it's free to go pull that shit on some other poor bastard.