Hm, it's hard to say. It's not so much the number of players per match that causes the problem; it's the fact that with any multiplayer game, players do NOT like having to wait long amounts of time to get a match going. The lower the size of the community, the longer and longer it takes. Even in something like fighting games, which are almost always 1 on 1; I've seen too many of those where they're pretty good, but the online part (or even offline!) just dies way too fast because the devs/publisher couldnt attract enough people to it quickly enough. Particularly when you consider competition with other similar games.
One thing that might help a TON, for any game making you want to do for any genre, is to find a good community that focuses on indie game development and such; you can get people to test out and try your game as you put it together, get help on issues you run into, and stuff like that. It could really help you get to where you want to go with this.
A good one to start with: http://gamejolt.com/
It's not too hard to get games noticed on there, and the sheer number of games of all types also means there's lots of things that you can take inspiration from. Good and large community there. Its exactly the sort of place to go when you're starting out with this sort of thing.
I'm curious though, just what sort of game are you looking to make?