Hi there

Gunners rarely explode though they may accidentally do friendly fire, and yeah they can fight too. For melee and morale reasons gunners are better. For your own reference, try making your own simulation games to compare units stats that u want to find out. Make a custom battle and bring the units u want to test, then hit F1 to see stats comparison. U may visit www.totalwarassembly.com as well to do unit stats comparison (the site is down at the moment).

Now the fun part . Try placing gunners in the front line on hold with arqs behind them then arbs/archers on the next row (put arbs/archers on the first row when the enemy is still far). Don't panic just put them all on hold and watch, AI troops might route nicely. Don't stop chasing them after they are routed, this willl create a mass chain route. Some cavalry support can help too. Be sure u have decent general to lead them on though. If that doesn't work for u then try using melee units as the first line.

This is something I picked up from Multi player games in Elmo's game. Wish I knew this in my early Single Player games. I didn't use gunners at all back then since the guide says it can explode. BTW this tactic is one of my excuse of getting more ice cream while playing MTW SP games Enjoy the show.