I played a game last night against space puppies.
My opponent had two Wolf Gaurd Battle Leaders in terminator armour with a four man retinue each.
Each squad had three assault cannons, two in the squad and one on the battle leader.
His reasoning is that the battle leader can take anything from the wolf gaurd entry, including assault cannon. Three retinue can have an assault cannon on every third model.
Two questions really
1. Can the Battle Leader have an assault cannon?
2. Do you need six men in the retinue to get two?
I didnt' mind playing him as he has to pay for them anyway and I found they didn't enjoy a face to face with a possessed aspiring champion with lightning claws.