It greatly depends on your skills and the creature skills. When I was fighting Dodge 3 creature I was lucky to get 3 out of 5 hots, most of the time it was 2 or less. But when I found something with low or none Dodge skill my average was 3-4 hits.
The leader is the last to die. This was a change some months ago to prevent the group from disbanding. Either way it is intended. Once the others are dead the leader will get hit.
Not only is the Leader of a bandit group/creature squad the last to die, it appears he/she are immune to taking any incoming fire until all other members of that squad have been killed.
I know this may belong in the Suggestions thread, but I was wondering: is there a way for the invulnerability of the leader to be turned off during the same combat round when the last member is killed? More than once, my squad has had only a few HP left to finish off the remaining non-leader, but instead of shifting fire to the leader after the first three or four shots removed the last remaining member, they simply blast a hundred holes into the dead body.
I wouldn't mid if they got exp for that, but of course, they don't.