Personally, I think this logline has a very solid hook. The main thing I felt was lacking was “wife” and “rich man” seemed generic. I was thinking “cheating wife” or “adulterous wife”, but I think dpg’s “unfaithful” works better. If I were doing this as a short film, I’d definitely also take his advice to narrow it down to one lover, and the benefit of the wife trying to get her lovers to kill him help you avoid having throwaway characters. Having the lovers interact with the two sides gives you a lot more opportunity to show their personalities. The benefit of having more than one lover is that you can do different things with those personalities, and also contrast them. Maybe one prefers the woman and the other is bisexual and warms up to the man. Maybe one is a vet that actually is good at killing, and another one is a nerdy accountant.