Wards are imo by far the cheapest way to kill someone and are especially annoying on small maps.
Would it be possible to change the code a bit so wards don't do damage and just slow? Removing the slowing part or lowering the damage part could also work or put a cooldown on it so you can't drop 3 at once.
I don't see a reason to change wards. They are very easily seen and can be avoided. If you are in a position where you don't have a route to take without being warded, then that is against the rules and should not be occurring.