I think mortars/howitzers could be a cool idea as a new mech weapon. Wouldn't work underground or underwater though.

Missiles are fine, dumb firing is where it's at. I agree with portable artillery, but changes in map design would need to happen for them to be cool. Unless we want to ignore the subtlety of hills and cliffs and just have hard set rules depending on map type. Underground would be weird, at that point the artillery piece horizontally than vertically.

It would also bring into question how the Colubra would be balanced around that, not that cheesing with cannons isn't already easy.