Destroyer pve clearing problem

hello i dont know if this will reach  someone from  dev team to  look in to or even if it will reach it  that there will be any actions made . i will try non the less
so at the moment destroyer is worse than invoker in clear speed , the simple solution would be to change carpet bombing casting speed and cooldown of the skill 
as of now  theres onlly few skills to play with in clearing huge chunks of mobs  like gambint / cannon / and the nuclear 
if carpet bombing cd would be around 8 seconds and casting time would  be reduced by half the class goes back again  on the equal footing of many other classes.

thx for time reading this if at all.
good day.