RTF is a global modification that replaces all towns in the game.

like in the third game

Well, in principle, it will be possible, but some icons and spell names will need to be changed, because, for example: where would you assign "Blessing"? Personally, I don't think it fits anywhere in particular. But "Blessing of Arkat" is clear - it's fire. And the main thing is to avoid what happened in the third game - everyone levels up earth and air, but no one wants to take water, no matter what.
In general, it can be tried.