When considering that I was going to be playing such large battles I thought it
better to keep time limits in place. They're usually considerably extended given
the size of the forces, which I would think is more than enough - I refuse to sit
for hours repeatedly skirmishing with horse archers. Generally found that if the
game was paused and I came back later [e.g. after sleep] my machine was
unable to cope and would have slowed down significantly, if not crashed.

Now that MTW no longer works on my system I miss those long bloody battles.
[Sadly, many 60 second Rome clashes will never compare.]