The web page could admittedly be clearer in specifying the number in the squad, but I see no reason to assume it’s anything but a normal 11-11 with subs. As 5 of the supporters, maximum, can be bought, that gives around 11 squad places (assuming 5 subs) to raffle winners, if it is 11-11. I certainly don’t think the club would advertise a raffle for something where all spaces could be just bought out for some 5 a side game.