The issue with TZ 3 is rolls. The rolls are exacerbated by being able to just take one connected town after another. This can happen within 15 minutes of when one town is captures if the attacker does it right. One side can potentially take 2-3 towns in an hour if they are way OP.
One solution might ne to require that a Town/ Brigade that is attacking must be at 90-100% supply when they attempt to set an AO in TZ3?
This would slow down attacks from towns just captured, because their supply would have to completely finish trickling in...They couldn't just take it and start attacking the next town as soon as they get the first supply trickles. That town/Brigade would be unable to attack until it's supplies were replenished.
This would definitely help prevent rolls from one town into the next, and promote an overall advance of the Front, as opposed to spearhead advances.
Combine this with slower Cap Timers and while it might not stop one side from taking towns, it would slow down advances based on resupply.
This could also encourage the RDP air war.
