It all depends on whether a combat system is something that should be included in GregTech, and if that is the case what other things should be included.
Personally Gregtech to me has always been about realistic tech progession but I did jokingly state once that I look forward to the day when GregTech became a be all end all mod.
At the end of the day it all depends on what Greg wants it to be. Things like combat systems, well you could always have another mod do that.