By the way, in Heroes 5, I find the fluctuating initiative of the hero himself quite frustrating. On the one hand, it's a unique feature, I agree, I've gotten used to it and wouldn't want to be without it. But on the other hand, in Heroes 3, you could mathematically calculate the tactics, especially the tactics for using spells, and plan it like a chess game.
But here, one hero casts a spell three times while the other waits for their turn... or maybe twice, or maybe four times. In some ways, this is a plus (the variety of battle outcomes and hero development paths), but in some ways, it's a minus, as it makes it too difficult to choose an overall strategy.
However, this is just my opinion, so please hold the tomatoes and stones.