He either farmed or bought tokens to acquire the Scout level players, and as dv8r says, trained them up to 7 star, this is possible at any level if you are willing to invest much time or money to have enough tokens, it would be many. (my team has had 6 & 7 star players since level 2 {got a link below} this makes the Cup very very difficult though league not so much hard.)

Both very nice teams!