I think that both BFG and B5:ACtA would deal with similarly sized fleets. B5 does have more detail, but it also plays fairly fast and I would happily pick up the same fleet to play either game and it would take about the same time.

B5 also has an interesting 'point system' for a game, designating a game as one of five battle levels, and this dictates how many point you have, and how much each ship costs. Bigger ships cost more in smaller games.

BFG's big advantage over B5 is that it is a lot easier to just pick up and learn quickly, while retaining a similar level of tactics, etc.

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https://www.cybershadow.ninja - A brief look into my twisted world, including wargames and beyond.
https://www.net-armageddon.org - The official NetEA (Epic Armageddon) site and resource.

I recently picked up the old Star Trek RPG (1986) by Fasa.  It contains the Starship Tactical Simulator, which is in effect a separate space combat TTG.  More of a mini Starfleet Battles, plays faster, but has good detail.

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