Don't ever quote tweet, but I was blocked by OP and did want to comment.
I feel like 2 would be a less valuable story, as it would be just a war for power instead of trying to upheave the social fabric. Number 1 can be interesting if written well
So imo, for Edelgard to start a war against the church would only make sense if:
1) Her motives are just completely based on what TWSD are telling her or
2) The war with the Church is just an excuse to conquer other nations
But neither of these things is explored
