Are you saying that Astarion basic armor should become regular 10AC clothing instead of armor?
If so i 100% agree!
Nobody will ever convince me that nobles, who have acess to all luxury and comfortable materials would willingly decide to made their formal clothing out of stinky and tough leather. :-/
Maybe not stinky and tough leather, but I don’t see why a noble who appreciated a bit of protection from adventurers with stakes wouldn’t wear a well made leather jerkin with a toughened breastplate and a bit of fancy embroidery and lace. Not that Astarion is necessarily mixing in noble circles any more, though that’s probably not relevant to get into here.
I mean, I’d prefer regular clothing to armour that gives disadvantage on stealth, but again there’d be incentive to swap it straight out for boring, normal looking leather. My preference is for Astarion to have appropriate starting gear for a rogue, ie leather armour, that he can wear for a level or two, that nevertheless looks cool and unique.
