My vote is 2. Thoughts on why: Mansa is already more advanced than we are. Our best hope is to outproduce him and that's easier, in my opinion, the less advanced everyone is. We could possibly go the whole game without removing Mansa, but I don't like his cultural pressure on our north. Sally piling on doesn't scare me in the least. He and Mansa are each others' worst enemy. It would take a lot to get Sally into the war and it would take a lot of time for Sally to mobilize. Now, losing Mansa might slow us down against the other continent. He's a reliable tech partner who will still trade long after the others fear you are becoming advanced. So, while #2 is still my vote, my next vote would be for keeping everything peaceful, building culture up north, and waiting until we know more about continent B.