I was just thinking about it conceptually, I agree with you, existing stacks shouldn't be invaded just so. They can stay (and then apply only for new ones) or the owners can be offered compensation, etc.
And about the 100 flowers, the number was a wild guess, but your answer makes me think it's good If it takes you, an expert herbalist, one day to farm it, it would take 'normal' people several, which is an appropriate amount of effort for revival in my opinion. And the fact that you can do it faster is deserved because of your dedication for grinding herbs.