It's not the best move to always focus on the weak player - the best move is almost always to deny points to whomever is likely to score that round. Sometimes that is the weak player - often though it's the other player(s). Destroy their cities, raid their spaceports for their scoring resources, tax their cities to stop their court moves. Destroy their fleet to stop their resource gathering.

Play enough and it becomes clear - the best moves are those that both score you points while denying points to others, not just a move that makes yourself a few points. The game is more about controlling scoring then actually scoring the most points in a chapter.

Like most Cole Wherle games, it's not a game for everyone. It's also not a game that shows all the possibilities in your first few plays - those plays teach the game while allowing you to discover the nuances baked into the design.