I've noticed that the A.I. has a plan to attack such and such city. So it marches it's army to such and such city but if it runs into a scout army( I use 1 unit ahead of my towns as a scout). They attack the scout of course 1 unit will get slaughtered so I withdraw. The only thing is the A.I. will not do a follow up attack slaugther the scout and continue on. So effectively you can hold off an advancing army forever with 1 lone scout. I only use them where watcher towers do'nt give an effective enough line of site and only want the early warning that they are coming.
What the comp needs to do is if it wants to take a city it needs to attack everything in it's path until it arrives there unless it runs into an army it does not think it can win against.
