Larian Studios Forums Baldur's Gate III Baldur's Gate III - Suggestions & Feedback Metal Shield vs Studded Shield

Both mentioned Shields provide +2 AC

Of course the Studded Shield could be build more robust and the Metal Shield is using not so much Steel.
Both are having same weight.
But i like to think that Metal is better then Wood, so why not stay with this general view and give Metal Shield +3 AC?

Or Give Wood +1 and Metal +2 AC?

Or anyone post some 5e Rules for an explanation?

PS:
Metal Shield looks more awesome on Shadowheart or a Fighter with a nice 1H-Weapon