It looks like Krakens have the same problem, which sounds like it would be solved by your fix. I think the Fall Further/RiFE code has something in it which keeps tracks of the caster + summoned unit link (and grants the caster some XP when a summoned unit wins a battle). Summoned Balors (with an AC bonus) are duration-limited. Order priests have pillar of fire (and unyielding order), Empryean have crown of brillance, while RoK has earthquake. For FOL Treants, I'd actually think it'd be kind of neat if it was something like 1 per 4 ancient forests in a player's territory (maybe modified by map size...). Or just 1 per caster, but maybe make them a bit stronger. FOL mostly seems to be an economy booster for non-elves (and a near-must for elves), since the ancient forests give you extra food and health. Or make the summoning of a treant downgrade the forest back to a new forest (with maybe a 'settle treant' option to return the forest back to ancient status)?