Which faction is the most interesting to play as, and what strategy do you find most engaging?

Why not any… Kifrah is weaker. Minotaurs are terrible in the fifth game. I tried to play with them. They are slow and have low armor. Furies and Stalkers are the best for dealing damage.;)

Well, why not? You just need to develop her if you need a warrior and not a mage in the endgame.
At the start, she is a little slower (you lose one day in development)
But when developed in:
Leadership (it's very difficult for another hero to get this)
Attack
Luck
Logistics
Summoning/Education/Chaos
She shows very good results.

And Minotaurs are only needed for the endgame (build them in the first week and let them accumulate).

And an opponent who doesn't pay attention to them at the most interesting moment receives a teleport of Minotaurs or their phantoms and starts to take a beating.

And regarding not bothering – I already wrote that the hero is the most versatile race in the fifth game in terms of tactics.