On the skirts, We only run 1 on Binky. A front blade of titanium which is held on by industrial velcro of all things. Conker 2 has massive angled armour but it still rests about 2 mm off the ground.

My logic with my first robot was that since other machines were going to get under me anyway I might as well give myself better ground clearance so I can drive off them and maintain control. It sort of worked but I never spend enough time in the arena to say for certain if it was better than skirts.