I'd like to add something of my own. I think the Sphere of Inhibition doesn't isolate units from the effects of mines because this sphere prohibits casting any magic in principle. And mines already exist. That is, the sphere doesn't neutralize the effect of spells; it prohibits their casting.
But at the same time, the Efreet's Fire Shield works in both cases, both with the sphere and with the cloak. That is, the cloak neutralizes mines, but native creature magic somehow doesn't.