Try and change the cf extender to a skirt.
I think a 40cm Polycarbonate skirt would be lighter than it, and provide slightly better and stronger stability.
is this bot don't lost all razors in a fight before do a damage thought
OH MY GOD IT'S JAWS!
Swap the irons for beater bars and LDS teeth and try not to stack the ants, use the other AP if you have to.Turning the sheet so it covers the wheels might help aswell.
From a realisticism standpoint? A hole could be cut in the sheet for the wheels. Just axle load them and maybe use tornadoes if you have the weight, if vlads are too small.