an idea to resolve the war weight issue.
If each account linked to 2 villages. The Nprimary village is a fix rule that can not be upgrade the until reach certain defense . The 2nd village can do whatever u want except the lvl must be 1 th lvl lower than the primary one. In war, both account will be enrolled in but the war search will only based on the primary village and 2nd village will not be in the equation. In this case, worst case is half engineered clan verse a full max clan. This will eliminate the engineering clan. Plus, either the max clan or half engineering clan won't really have advantage as it still all about your attack on the primary village.
The only issue how the current village without maxed defense join the war? Coc may lost a lot of player by doing it.
One possible answer is start a new clan/war league for this type of clan/village and let the old war league continue on it own.
For the player already have a mini account, they are allow to merge 2 together as long as the primary met the criteria. Or the player can start a new Secondary.
For those rushed on defense, they will not be allow in the new clan/war system but stay at the old one. In other words, slowly phase in the new system and phase out the old system.
Cheers and have fun.