I once tried a similar build on the Mauler with 19 DHS and fully skilled for heat-efficiency.
In my opinion heat was quite manageable, the racs usually jam anyway before you overheat. 3 racs are fine with 10 true dubs so 9 additional external DHS can barely support a fourth RAC + ghost heat. The real problems however are top speed, size and hitboxes.
Though while 4xRAC2 are devastating you lack the speed to get into position quickly enough or to get out if things get too hot.
Additionally people of cause prefer shooting the assaults and the Mauler as well as Cyclops hitboxes are quite easy to hit.
For comparison the Bushracker is not only fast enough to take advantage of opportunities, it's also often ignored when standing beside bigger mechs. And if it's shot at damage spread naturally. I have no fear staring down most assaults in this thing when i have room to stay in motion, and i even dare to run an XL engine!
So in a Bushracker i can deal much more consistent damage with only 3xRAC2 than with a quad RAC2 assault.
Edited by Daggett, 14 September 2018 - 06:47 AM.