A little late for the discussion but maybe the devs could consider some dual immunities for the troops like:
- Thick Head: Immune to Stun and Charm.
- Iron cast guts: Immune to Poison and Disease.
- Warded: Immune to Deathmark and Cursed.
- Mana Shield Immune to Mana Burn and Mana Drain.
This would add a little more value to some traits and the troops itself. For example: Pride Guardian with Thick Head making him immune to Charm too would help his team since he wouldn’t deal damage to his allies, removing their armor, and making his spell weaker. And by the lore it also makes sense that the guardian wouldn’t hurt the ones he is protecting. 
Thoughts @Sirrian ?