this is a good point for selling a slave to a new owner, but it really doesnt work out for specializations.
which, i am of the idea if they had to fix this in some way it should be a way that could just work all around. if you have your slave stripped for specializations then you have to regear them for each slave that gets a specialization. it would be very annoying compared to them walking in with their clothes on and coming back to the mansion the same way. on the other hand putting in a way for it to check basic stats allows it to continue to operate as it always has in that regard. additionally, that same checking can be brought over to quests for slaves (like the starting quest for mage order, and repeatable quests).