Right before heavy clip was altered, in a 1 v 1 pyra fight the mortar and the light flak used to be almost perfectly balanced.
The mortar had 16 shots, no spread and almost unlimited range but was harder to hit with. The light flak had 4 shots, no spread with heavy clip, very high projectile speed, better gun arcs and and made a quick 1 clip kill.
Mortar had an advantage over flak since it could assist in the armor break and still have shots to make the kill (this was before gats 1 clip killed armor) giving the mortar ship the ability to get the kill before it's own armor went down. However nailing the shots was difficult and there was a chance that the enemy would rebuild their armor before the mortar finished it off allowing the flak ship to win the engagement.
We don't need to go back to that sort of knife edge balancing, but for 2-3 weeks it actually existed, so I know its possible.