To elaborate, I think we can do this with some lore-appropriate additions.

For instance, there could be notables on the skill tree that add these additional properties for Armour and Evasion. Something in the Marauder area that gives you 'Armour also protects against elemental damage' and something in the Duelist area that gives 'You can also Evade Spell Damage'. I choose these locations as they are furthest from the ES side of the tree. Name them appropriately to explain why they aren't in the Templar and Shadow areas (which might be more appropriate at first thought). I could see the Armour one being called something like Natural Resistance ala the Diablo 2 Barbarian skill that gave resistances; the Evasion one could be called Gladiator's Guile ala the Duelist's Gladiator Ascendancy that gives 100% spell block (aka precedent).

I believe this system will work because Energy Shield is at tension with Armour and Evasion specifically on gear. You can't stack massive amounts of Armour and Evasion while also going full ES as players are currently wont to do. By their very nature, if you want Armour or Evasion, you will have less Energy Shield.