More Abberrations, was: General walker stuff from the peanut gallery :o)

OK, again, caveat: I'm not a big mecha fan, especially the big stuff ala
BattleYech, but in some fictional backgrounds, it can be fun. So I had another
idea for a walker variant, one I think has been done in fiction, but I've
never seen discussed here. What about what I'll call "Centaurish" mecha,
either quad walkers with the upper torso of a biped mech, or the
tank/mech mishmashes ala certain Gundam units?  Anyone ever try those?