Some heros do not affect the hero limit. how can I fix this?

I'm making a map where your suppose to capture enough targets to get resources and when you get enough it gives you the ability to go into your opponents base. As you collect these resources the hero limit increase and goes up to 7 (the max number of hero icons that can fit on the screen).

The problem is, whenever the player purchases a goblin tinker, alchemist, or a firelord (my 3 most favorite heros in this game) it doesn't seem to affect that.

At the begining the limit is 1 hero. With this problem the player could take one of each of these and then some other hero from the tavern or their altar and get 3 more heros than their opponents has.

When the limit has been reached, these three heros are unavailable just as all the other heros are so that's not a problem.

They're still affected by the fact that you can only have 1 of each hero type.

Can anyone explain to me why this is happening and how I can fix it?

Advanced>Gameplay Constants>Hero Limit or something like that

-Av3n

Advanced > Gameplay constants > Techtree - Dependancy Equivalents - Hero

Make sure all the heroes on your map are on that list.