What? When did this become my strategy? Your point was that summons should not grant experience - I linked a replay of a human playing defensively and using supply-less summons to harass. That wasn't the only thing that happened in the game and it wasn't the decisive factor either, but it was still an example of why summons should grant experience because otherwise you would promote such mindless use.
I think it would be fair to have all non-item Hero summons (besides Mirror Image, but who uses that anyway, amirite?) capped to 2 per type.
Tower rush with 3 level 2 Water Elementals, Militia, and a Tavern Hero is literally unstoppable by any race except Undead, ofc.