Heh. If it helps, I managed to take garrison archers with me once. [e digicons]:blush:[/e]
They messed up my units list and counted like killed solder for "give art" action.
One was killed and another left an army in a couple of turns later.
Even I managed to reproduce it, but I am not sure:
1. have creature at garnison.
2. survive the siege.
3. make clicks on empty portraits using shift
4. get free archers.