Maybe. Currently the level 4 forts have two huge advantages over level 3--no retreat, and very slow degradation. The no retreat rule is ridiculous when the fort is practically undefended and huge odds still force no retreat and little degredation. I think maybe somewhat higher odds to force retreat, depending on the terrain, and faster degredation might be a better compromise.Fort at level 4 or better will not prevent defender's retreat if there will be no town, city or urban terrain in hex.
This seems fine to me as long as low-odds attacks don't force degradation--that would invite gamey tactics.Bonus fort destruction in combat will be rounded up, so at least 0.02 of fort level will be removed at all times.
Something else regarding forts that might be looked at is how fast level 3 forts can sometimes degrade. I sometimes see 1:1 attacks result in compete destruction of level 3 forts (while other times the fort degrades just a little). This extreme difference between level 3 and level 4 fort degradation is a "game changer".



