The choice between Close Action (CA), Wooden Ships and Iron Men (WSIM) , and Flying Colors (FC), is really one of the number of ships to be controlled per player.

CA is really a one player per ship game, although a good player should be able to handle two. So Trafalgar needs about 30 players minimum, and more is better. I've done it online twice, never face-to-face.

Our club prefers 'squadrons' of 3 to 4 ships per player when playing WSIM. 6 is doable, but the firing slows things down quite a bit. Trafalgar can be done with the historical squadron division of 5 allied admirals versus 4 British, though roughly double that number is better.

FC is more geared towards fleet actions. My preferred FC scenario's have roughly 10-15 ships a side, and can be played one on one. Trafalgar is OK with 2 or 3 players per side.