Tweaking Sunder Charms for better balance

Too complicated.

Better is to have Sunder Charms not reduce resistance at all.

Just have it so Sunder charms allow all minus Resistances to break Immunities, and apply without 1/5 debuff.

Details here:
Ok, changes i would make to those charms (assuming they are a going live) - PTR Feedback - Diablo 2 Resurrected Forums (blizzard.com)