Unbalanced in Breakthrough

I unlocked a shiny new support gadget today , the mortar - great i thought until i tried to deploy it as an attacker in breakthrough. In one match the defenders had 3 mortars on the go and the attackers were getting pulverised.

The balance in that match was the absolute worst ive ever encountered in any of the previous BF titles. It makes no sense that the defenders have unlimited amounts of mortars and the attackers get zero unless u get so close to the front line that you dont stand a chance to use the **bleep** thing. A crazy choice imo.