Jantz, I would very much appreciate it if you could attach the mod and an image of it to the message. First, it won't be lost if the file storage period on the hosting expires. Second, the image can be viewed directly from the browser without downloading it to your computer via the hosting. If you are interested, you can find out how to do this here.
However, the idea of using resources when hiring creatures deserves attention in a different context, namely if the map starts with already developed cities that cannot be built up during the game (although, unfortunately, I have not encountered maps of this type, except for RTAs - but there it is an arena (leveling up + final battle), not a map).