How I would change 1UPT Ranged units (before tanks) can no longer defend themselves. However, they can now stack with other units and have a slightly increased bombardment strength. Civilian units (including scouts) can infinitely stack, regardless of civilization, although workers still cannot work on the same tile. Movements are only ever cancelled if a route is blocked on the turn before they will get blocked, not so many turns in advance. It should also be far easier for units that can stack to move together. This would solve a lot of problems for me. It would keep the tactical elements of the game, I'd say increase them, but not force your military to be restricted. Allowing more units would mean that the relationship between teching and production could be far more balanced.