I thought this was one of the few great ideas on the forum, I think it was Chris from Outlaws that posted it originally, along with gail's 10* defense idea, that actually made a lot of sense. Of course you'd have to replace 'avg level' with the war rank calculation, but it seems like a pretty good idea. It lowers the weight of Iron-GP bases. This both prevents global/industrial alliances from lowering their averages by any material amount, and also keeps the alliances truly built with Medieval-EA bases relatively safe from being matched too high.
Im sure there are holes that can be poked in it, but to be honest anything is better than what it is today, which is a nightmare.