Do we know just how much stronger the "Stronger Stimulant" upgrade makes the potion the alchemists throws onto friendly monkeys? Do we even have the stats to tell how much Berserker Brew and Stronger Stimulant benefit our towers?
I don't think so, but we do know that it's borderline OP based on gameplay. That first path (4-0-2 to be precise) paired with Super Monkey (any path) and a Bloonjitsu/Grandmaster Ninja annihilates CHIMPS on most beginner/intermediate maps. Without the alchemist the strategy isn't viable at all, so we do know the buff is very significant.