Teemo shrooms should be easier to kill

Its very frustrating going against teemo when I have to dedicate the same amount of time with my sweeper lens to killing shrooms WHICH DEAL DAMAGE as I do to killing wards. 3 hits is a bit much for something that can deal like a thousand damage easily. He poops out like 3 a minute and they deal oodles of damage and slow so therefore they should be easier to take care of. At most I can kill like 3 in the span of one sweeper which is a high cooldown and its not feasible to carry pinks and just place them in awkward unstrategic places to remove shrooms.