So far the two most combat saavy mechs IMO are mine and the liberator. The patton is to slow and needs escorts is the only reason id say those two.

Also I wouldn't really consider Leo's an HK I=he is more of a scout mech. His chasis is made for mobility, but the weaponry compared to most mechs is actually inferior (perfectly normal for a light mech). If you were to stack up say mine which is an HK build to it he would have a really hard time. Also put the liberator or yours up against it he aint going to do much more than either get turned into swiss cheese o=by liberator or blown the hell up by the patton. Whereas my plasma cutters if I got in range could do damage, and the damn railgun is really effective as well. Balance is key in an HK whereas he has mobility and CQC all the way.