It indeed seems a bit unreallistic But no, this player is not my only 6 stars player. I actually have 5 players with 6 stars, and most of time at least 4 of them are on the field.

The season is almost finished, so yes it is worth it to wait for the next season and see if he does better. I just hope that my stricker, who is also a scout, will keep going with his actual performance.