I just wonder if FoF will work fluently with larger numbers of tactical units - some of the scenarios in the Bush Wars book are huge. I just hope I'll get around with the 40-odd guerillas I have lined up for painting now...
From my somewhat (sadly) limited experience of them, they work best at an optimum of a reinforced platoon.
They do cope with larger games, but like anything, the more units you add, the more it inevitably slows the game down. It still flows well enough though, just takes longer to work through everything. At a push and with plenty of time on your hands, you could play a company-sized game, but that's the limit in my opinion.
Less than a platoon, I would go for something like FNG, Platoon-ish is FoF territory and for a bigger game I would be tempted to try Bolt Action, despite it being supposedly a platoon-sized game.