@Elusive you know, a difference in slots is not sera advantage. It is a double-edged blade. Yes, sera can use t2+nanoregen, but he cant use nanoregen+RAS, for example, while UEF can.
Also UEF have t2 field engies, so there is no problem in making some stuff on the frontline for him
And yes, in the late game +70 or +50 regen on com is not a thing that can really change situation on the battlefield. It's useless against snipes (com will die too fast to +20 regen matters), and gives almost equal ability to survive as UEF com with his CHEAP +50 nanoregen and his veteranicies which he gained on t1-t2.