Well, that attack on Chernobyl has pretty much convinced me that something needs to be done about walls and str. Tunneling through 4 layers of the strongest wall in the game in less than an hour, without even having to build any large, cumbersome siege machinery, seems...silly. I think a lot of it has to do with strength and damage, which also has the effect of promoting long-term players to relative gods.
How about, instead of a flat "damage is 1/3 strength" system, strength affects damage on a curve, as with quality and so much else in the game? At first, newbies would see quick results, but as time goes on, it would take more and more strength to change damage level....