Funky campaign you got here, i think this is the second time i play this kind of map/campaign, there was another one i played called
The Legend of Magnador with this kind of similar type of fights, what can i say, i enjoyed playing it, not sure i am a fan of the hero not taking part of the fights tho, only staying on the hill and using just his spells is kinda lame in my opinion.
I liked how we could buy different types of units for the army, that was cool.
Not sure what the items are for also, since the hero isn't taking part in the fights, so the only items that aren't useless are the int ones since they give mana for the hero to use more spells during the fights.
I suggest to give the Legend of Magnador a shot, you can learn a lot from that campaign since its in similar style!
This project has lots of potential, i hope you will keep working on it, Godspeed!