Damage or Fire Damage perks (shooters only)?

Considering Cannon, Explosive Cannon and Blast Cannon. (skipping sniper cannon as crit chance is the best perk for it).

Speeders and enforcers generally target a single enemy, and they may do this thing (first setting on fire, and then a blast cannon from close). But shooters and defenders are generally encountered with 2 enemies.

Fire Damage perks give more damage % than general damage perks for all cannons.
But isn't it difficult to first fire, and then accurately fire the same enemy without a miss before the fire ceases?
The player may hide, or go back again into its team, and it may be difficult to shot again after firing.
In whole game, we'll find enemy who is burning to deal more damage rather than finding the enemy who needs more damage

General damage perks give damage irrespective of fire, though it may be lesser % than the % given by fire damage perks.
Or more simple, with rare damage perk, each shot will be 106%. With fire damage perk, each shot on a burning enemy will be 109%, and for not-burning enemies, it'll be just 100%.
Which is better- damage or fire perk?