1. Make all units based on heroes and disable the hero icons for them.
But imagine if he makes a game based on armies, where each player can spawn armies at least 100 of them, meaning we have 100 Heroes.
Heroes are a unique unit in Warcraft III that cannot go just like that, compared to Normal Unit, when it dies, it truly dies (cannot be revived).
But I think we can counter this issue by removing the Hero when it dies.
In GUI, you can read the Note below the function box it says "Leave no corpse. If used on Hero, that Hero cannot be resurrected", this actually means that it will treat Hero Unit just as Normal Unit.
But I don't know if you remove Hero like 100 times it will cause bugs to the game or not.
This is the only viable solution I can think of, because the EXP Bar on the Unit's UI is hard-coded, meaning you can't simply make it via trigger or what, you
must make it a Hero to enable that EXP Bar on the Unit's UI, unless you want it to have a Floating Text of EXP Bar (or Multiboard), you can use Normal Unit for it but this will mess up the game if you want to keep track like 100 Units at a time.