In Cheat Engine every player have position data. 6 players is frozen, but you can unfroze values, and player appears on field. You can 6v6, 7v7, 8v8 etc.No chance adding larger field, and 6vs6? Thats how we play in Hunedoara, romania. I like to add my mates in a team and play whit them. Or maybe if it's not that complicated for us mear mortals, u can tell us how do it.
Here, Home players and his positions, and away team players.
Larger field you can edit in fifa_ng_db.db in stadium section.
p.s. alas, this mod is abandoned, as the AndreaPirlo left the forum. I could continue the creation, but I have no time for arenas create and no people who are willing to help.