My idea is adding new building similar to rocket factory with a difference of that you assemble weapons and adding new level of weapons but no and level of weapon buildings.
for example
lev 1 weapon and lev 7 weapon produce new lev 8 weapon
lev 4 and lev 4 = lev 8 weapon
or 8 lev 1 weapons produce lev 8 weapon
or 4 lev 2 weapon
and limit asemble plant production
for example
level 1 assemble plant -management work to produce 20 weapons with no workers or 20 weapons
level 2 assemble plant -management work to produce 20 weapons + one worker or 40 weapons
level 3 assemble plant -management work to produce 20 weapons + two worker or 60 weapons
level 4 assemble plant -management work to produce 20 weapons + three worker or 80 weapons
level 5 assemble plant -management work to produce 20 weapons + four worker or 100 weapons
With limit of how many level 8 weapons you can produce he will be elite weapon and we will give value of low level weapons of course this numbers can be different and addicted to country resources of owners account.
Sorry for mistakes english is not my first language.
