I've mentioned this to a few people, but never get so much of an acknowledgement or reply about it so i put it here.
seriously easy fix for othuum's terrain issues would be simply to put the low high-dps cannons onto LOW-ARC firing, rather than direct fire.
sure they would still hit the ground sometimes, but they should be able to shoot over at least minor bumps now. this is similar to how most uef weapons work like pillars/triads/fatboy, etc...
no need to shift dps from rapid fire cannon onto the slow cannon, or change ranges, or raise the tank model (although that would help a bit too)
that a weapon so low to the ground is on direct fire is stupid, i'm sure it is like that simply because almost all sera weapons are direct fire and they were keeping with the theme... but everybody knows how crippling this is. Shifting dps to the slow-firing, long-range cannon which seems to be the popular suggestion has its own balancing issues to take into account like overkill, increased range on high dps, and low cannons still hitting the ground.