Major Damage is claimed to be well over a metric tonne, having seen all the hardox and batteries in that thing I wouldn't be surprised if it was :P The only way to really 'beat' it would be to try and disable the tracks, which would probably entail jamming your own robot in them, and then you have an annoyed Jonno and a robot slightly parallelogrammed from the tracks and potentially rather broken.

Battle Axe is lighter but faster, has a rather large hammer which can quite easily damage featherweights through shock to the drive, and the claws are probably capable of doing damage to a poorly put together robot as well.

My advice...don't go after them :P