10% resistance is quite a lot in the long run though where spells start doing 200-300 a hit, that's 20-30 damage off you that can prevent the shield from breaking.
It synergize with the lizard breath anyway that, with scaling, becomes quite strong (at level 12, it does 99-110 for 1 AP with no int scaling while fireball, for 2 ap, does 114-127, both scaling with Pyro.)
This synergy and ridiculous scaling makes it very tempting to always go for lizard race if you plan on playing a pyromancer. Less damage on self while having cheap yet very strong cone fire spell.
breath is less attractive because it cant get height bonuses.
Unless your height bonus is 80% damage, that 1 AP skill will deal as much damage as you do with 2 AP.
AoE shield mage won't mind getting in front anyway. My level 12 Fane has 320 phy and 509 armor and enemies do whatever they can to avoid hitting him. Too bad the evasive aura is a thing so if they can't kill him, they can't hit anyone.