I had something like this too once.
I made a map with something like 30-35 shermans one one side and 10 king tigers on the other side (allright I was bored!).
I fired up hotseat play and just did nothing and watched.
True to expectations the score after 1 turn was 5 shermans left alive vs all Kt's.
Next turn only one sherman was still in the land of the desperate
Just when I decided that this was too pathetic for words something happend!
This one sherman started "rocking" back and forth (driving about 10 meters forewards and back).
I could see that it was targeted by up to 5 Kt's at times, but they never managed a shot. The sherman stared to plink at the KT's and in the course of 9 turns it managed to destroy 4 KT's! (track hits, gun hits, crew abandoning).
After this it's luck finally ran out and it exploded. I must say this was very exciting watching and it gave me a whole new respect for the tactical AI.