Those kind of cases are usually much less frequent than new users that are speculating about it.
But really, it's not like it would be that easy on this level to fix passports (it's not a regional vodokachka league, you know), so if something can be done in that regards, it had to be done at a really young age.
But in terms of this team, I recommend anyone who has such a suspicions to compare player's photos to your own photos at the age of 18 and tell if anyone looks noticeably older. It takes some time (not too much though), but for some reason I noticed that people dissapear from those kind of arguments after it is done.
Btw, I also do this kind of comparison, but not because of any suspicions, but in hopes to better guess the biological age of the player and I can tell that from this team only Galenyuk looks older than me at the age of 18, but I think the reasons for that are quite obvious for anyone who have seen him.