Because "Wubba-Lubba-Dub-Dub!" Get it? https://mech.nav-alpha.com/#48b45e35_TDR-5S-T It can alpha 2.5 times or so before needing to cool down. Also it is quick and agile. Yes, the LPL can be traded out for 2 more MPL's and more engine but I prefer the extra range.
No ghost heat, but no cooling either. Losing 4 DHSs will lower dps significantly. A good way to avoid ghost heat when boating MPLs is to replace the excess MPL with ERSL. Very similar range and cycle times so they fire together. You lose 2.75 points damage per alpha, but generate less heat and get 1.5 tons to put elsewhere.
My firing groups are the 1)LPL+3xMPL, 2)4xMPL, and 3)LPL. No ghost heat firing this way either. And when I do alpha the ghost heat from 1 extra MPL is negligible at best. Also with the DHS and skills it cools very rapidly. I also tried the 2xLPL route initially and found the extra 4 points of damage not worth the extra heat.
Not sure where to credit this, but after scouring and trying all the thunderbolt builds; I realized it was Carlo's build written above that was closest to it (-1 ERSL). Gotten this hero mech from a sale a few days ago and finally decided to build it. Only has like 3 Skill Points..