What kind of magic do you like?

You can steal the Immortals. You can also steal Morale. Then, if you're lucky, cast the Magic Steal spell. I summoned them twice, and I ran out of mana.

Even if you can't cast all of that, Djinns, heroes, and sorceresses have illusions, which allows you to summon creatures just as well as a Druid, but using less mana.

And when will you have time to do all of that? It seems like a 1v1 match is being considered, a Druid against a Mage. It's an option, but by the time you remove the enchantments, steal mana, and do all that, the Mage will already be :smile34:, and the Druid's army won't just stand around :smile13:
And how will you deal with illusions against Black Dragons and Minotaurs? :p I don't think it will work. Summoning is simple and reliable, although it's a bit expensive for tier 3-4 creatures, but it's worth it, in my opinion.