What about we allow 2 handed Transmogs for the main hand while carrying a Shield.
Look BFA’s Cinematic, most of Alliance Troops carry a Polearm and a Shield but actually this is impossible in-game. I would love to transmog a Two Handed Weapon which is bigger and we would have far more options for cosmetics.
Also animations while carrying 2 TwoHanded weapons while being fury are the same as 1hded and shield, so shouldn’t be a problem.
About Deffensive Stance it would be awesome that your character would be actually using (only vissually / cosmeticlly) a Shield.
I think it wouldn’t damage any aspect of the PvP gameplay