Easy win
When you customize your bot at the begining of each weight division, choose one or two hammers as a weapon. It does not matter what kind you use, as long as it is a hammer. Attack your enemy head on with them to gain high aggression points. Rapidly use the hammers and you may destroy the other bot. Also, by using a hammer and your bot gets flipped, you will easily be able to flip it back over on to its wheels.
Bonus arenas...