The reason I slightly favor build 2 is that my regen always falls short vs. mechs of my rank. IMO 2000 HP is sufficient to provide protection, and Desert Fury allows me to get into longer ranges so I’ll be damaged less. Energy with Valiants and Ash Creators always win vs. , so I need some defense.
For me, 145 HP is less useful than a buff to damage and long-range capabilities. It grants more combos and potential victories over build 1.
Sure, Mercy hits hard, but when drained. . . sometimes not hard enough. I need more regen to soften the blows of energy. . . 253 regen would be a good amount.