Yeah, I am still working this out. It needs enough mass to be felt by the other bot, but needs to be light enough to get some speed-up.

Walking is never going to beat wheels for pushing. I'll just have to live with that. I'm hoping geckskin will be commercially available so that at least we can withstand a pushbot.

Armour-wise, I am confident you won't get through it mon. I'll be using sheer-thickening fluid on the kevlar. It keeps out a 50cal bullet, so you don't stand a chance of penetrating it, frankly. Blunt-force trauma is a different matter.

And of course walkers are inherently flippable.