Heroes 6 - Discussion

There's nothing to figure out in this system. If it's difficult to understand how it works, you can just look at the ATV scale; everything is already calculated 100500 moves ahead.

Um... the thing is, let's say in Heroes 6 or Heroes 3, I cast, for example, a speed buff (it doesn't matter which specific one, just a buff that gives speed) or a slow on someone, and I can accurately say who will go before whom and how, and plan my turn. In Heroes 5, however, a mass speed increase increases initiative, while a slow decreases it... it's impossible to predict the exact turn order after applying the buff, and I don't like to act "blindly."
In my opinion, this is one of the main drawbacks of Heroes 5.
If someone can explain to me on their fingers how to approximately calculate it correctly, I would be very grateful.