Armour of Agilulf query (Brets)

I suspect this is a left-over of 7th edition, where the rule was that a "character that is not allowed to carry ordinary shields is not allowed to carry magic shields" (p.121). This restriction does not exist anymore in the 8th edition.

Of course, I do assume you have not given him a magic standard, because that precludes him from carrying any other magic item.

To add: In the 6th edition ABs (like the Bretonnia AB), BSBs were generally precluded from carrying additional equipment. In the 7th edition, that was only the case for the first two ABs. I always assumed this to be a left-over from the 6th edition, and would allow my opponents with those ABs to give their BSBs shields, if they wanted.