You are talking about fully mature molly males and they cannot reproducing without females. A 10" pike won't have any issues with eating all molly females and even if she's full, she could continue mauling other fishes. As I've said this, pikes are greedy predators. They don't have any problems putting fully grown red rosies (3-4") away. They are eating feeder goldfish for sakes.
Your idea is nice but it will fail miserably 100%.
