Fortress versus Necropolis.

A perfectly viable strategy – except for leveling up with a mentor, I do everything the same way – I just don't summon creatures or level up the central hero in long games if there's no mentor, as it's not always possible to level them up. The only thing is – Helmar is a complete weakling against tier 3 magic – that's too much, considering that he doesn't really need summons either.

There's only one question – why specifically upgrade dragons?