You could reduce the limit by how many varients needed for example say that you want to put this guy in
http://www.sarna.net/wiki/Flashman you could release that mech but it dosn't have to have 3 varients to be mastered just because it dosn't have enough varients also you could triple the XP needed for said mech perk to make it not just a quick grind. Then once a second varient comes out you reset the mech xp but all the XP reset is given back as general xp then they can re apply it but the XP cost is cut in half if the 2nd varient of a mech is released and if the 3rd then it goes back to normal "Heroes do not count for this mech varient thing only normal but they could be mastered stand alone.
If anyone else has any better ideas feel free to suggest them here I think mine is solid enough.
Yes I know some spelling and maybe even some grammar I will fix that later just think this as a rough draft. But I wanted this idea out of my head before I forgot tomarrow morning.
Edited by Whatzituyah, 10 March 2014 - 07:54 PM.