Adding to Alex's post top, it is very doable but you've got to consider it's all about driving, you need to make up for the weapon deficiency in every other aspect - speed, control, power, armour...

I'm planning to upgrade the new HW2 into something more than just a pusher, but it's only going to be as an aid to the pushing ability, partly because I want an active weapon, but mostly because to have a successful pusher, you need to be a half decent driver, which I'm definitely not with robots!