Since my character is a stormcloak when I travel I often get bump into a group of imperial soldiers with one of my brothers held captive. When I try to give him armor and a weapon to fight off the imperial soldiers to my astonishment he doesn't wield the armor and the weapons that I give him. Why is that? The armor/weapon that I give him aren't cheap either.

Useful question - I would like to know about this too, if anyone knows?

It's definitely a glitch, so you shouldn't give too good equipment to them.

When i found out that it's useless i gave him nothing,and I Just freed him .

It's the gesture that counts.

He doesn't use them and sometimes he turned hostile when given armor and weapon.
Result : He was always killed by the imperials or by the player..... Now I snipe the guards from a distance and don't even free him. When the guards rush to the player he just runs.