Custom Maps without Custom Units

[Cyber]

Hey guys, I've gotten back into this game with friends and been loving the custom maps. My only question is if there is a way to replace the custom units back to original vanilla units? There are some great maps out there but not really wanting the custom classes they come with. Ive had some success on some maps replacing certain files with vanilla ones but it comes with some bugs like no heroes or missing classes. Hate to be the one to ask :c