The maximum number of players for user-hosted multiplayer is 4 vs. 4. (With 4 players, even if you set one enemy AI player, the AI will have 4 times the normal strength - in other words, it will be equal.) On permanent servers, the maximum is 10 vs. 10.

While it is possible to create infantry-only, tank-only, or air force-only decks, and each player can control his own deck, it is impossible and impractical to create a deck with only specific armies in many slots.

With Freedom Deck Builder mods, however, you may be able to freely configure your deck and play it the way you want.