The Aquila Stronghold is the new compensator
The whole 535 pts comes with a em-placed gun, the Aquila Macro-Cannon. The gun is a 72" Destroyer Weapon with an AP1 primary 2. You can also fire it with a quake shell that gives you a chance to knock air out of the sky with its sonic boom, and does an apocalyptic mega blast.
It is a Large building with a bunker that also has an armor value of 15 (yeah armor 15) , when rolling to penetrate it you subtract one and it also can be upgraded with 4 em-placed heavy bolters. Yes it can be taken down by melta but that can be nullified by placement and creating some buffer with troops around the emplacment.
If this is not broke I don't know what is.