Penal Legion guard are a very over looked unit in a guard army. They are only 80 points and I must admit they may not be the best units but there is something about flavor.
Some army choices are for meta gaming but this choice is for pure enjoyment.
I used Catachan bits mixed with Cadians and Marauder's hand axe bits. I painted 9 orange and one blue. Next thing I knew I had a group of psychos wanting to gain their freedom through throwing themselves in the storm of combat.
But for some reason I keep rolling the gunslinger (assault 2, 24 inch range, lasguns). This is not bad but str 3 against Marines is not great, being able to assault helps.
This aside the unit being stubborn really delayed the enemy. The unit is overlooked quite a bit due to it not having heavy weapons. Sometimes I get the rending ability and they become better in combat, but not by much. Again the point cost is low and they are troops so they can hold objectives.
I think if I field two units I might fair better.
The biggest factor is the wild card I myself do no know the plan of attack. This makes it more interesting as how can u counter an army you faced before that keeps changing. Plus if they die there are always more convicts wanting redemption.
Only the High Lords can forgive the heritic, killer, and the damned.