This design is fairly viable, even without the endo and ferro upgrades: I like how the LRM launcher allows you to provide viable support to other teammates outside of direct visual range, and how vicious the medium laser pack is when you get in close.
Darkthought's variant looks nice. Alpha from a 6th medium laser sounds a bit too hot with only 12 DHS anyway. though instead I'd put the TAG in the right torso and 1 or 2 ML in the arm. TAG higher = easier locks from cover position; ML in arm = more maneuverable close range defense. Kinda suck that I'd have to brutally murder my favourite 'Synergy' build and buy LRM20+A, but with recent buffs to LRMs I might be pleasantly surprised.