Well, Jeddite and Deemer are definitely better than Shakti, because, as you can see, the Dungeon castle is clearly focused on magic. So, it's probably better to take a hero with a magical specialization, especially since that role involves such a powerful magic. However, this is just my IMHO.
Ha, but what can Jeddite and Deemer do if they move away from the castle and there are no wells, villages, or castles where they can replenish their mana – fight with zero fighter stats? And in the final stages, if they get hit by a red orb or a cloak, what will they do? At the same time, nothing prevents Shakti from also greatly increasing her magic power and knowledge, and also learning the 4th and 5th levels...