Okay… so I'm horde training my Shroomish, Buneary and Elekid on wild Zigzagoon to get Speed EVs. Elekid is holding a Power Anklet (boosts Speed EVs). Buneary is holding a Macho Brace (doubles EVs gained). Shroomish is holding a Power Bracer (boosts Attack EVs) for when I train later.
When I check on Super Training to see how they're growing, Buneary and Elekid are both growing in Speed. Shroomish, however, is getting Attack EVs. The only thing I can think of is that the Power Bracer is converting the Speed EVs into Attack EVs.
Is this the case? I've never read up on it before.
EDIT: Just tried this with my Hondege holding a Power Lens. The EVs were split between Sp. Attack and Speed!