Very old topic...

[Sir Og]

I have thought about it and I don't think there should be a cap on number of units per tile.

I think what is missing is stacked combat (it has to be done right of course). There should be a limit on stack size, and that limit should be influenced by techs, generals, civics, promotions etc.

Another thought: stack size might be unlimited but support should become prohibitive beyond a certain limit.