You need to keep a couple of things in mind. The first is that if you book separate tickets, you don’t have a connection. Just two separate tickets, so if your first flight comes in late/is cancelled, you’ll most likely face buying a new return ticket to MLE at walk up prices. You are unprotected and travel insurance won’t be of much help to you. The second issue to consider is what countries you’ll be allowed into or to transit through. In general, keep it simple. I agree that you should rebook this as a single return ticket.