I have already pointed out this huge inconsistency issue in this post 
. but yes you are right, it should also be specified that he has 4 years of experience in the army. I guess it’s even more relevant to correct Sojourn’s age by adding another 4-5 years to her.
considering they recently resolved the error on Alive’s flashback on pve cinematic, I really hope they take THIS and Kiriko’s feedback into consideration. 
from an old post by michael chu talking about Ana origins photo (from old forums in 2016):
Answer: The picture from Ana’s origin was said to be 20 years ago. She’s currently 37, so she joined Overwatch at the age of 17. By then Overwatch had recognized her ability as a renown surgeon and has a masters in Nanobiotechnology. How can that be possible?
Michael Chu: While Mercy is extremely intelligent and completed her education at a younger age (and in a shorter amount of time than usual), she definitely did not join Overwatch at age 17.
where is the problem? 
have you calculated Mei’s 9 extra years in hibernation? the developers have always specified that the one on the biography is only Mei’s biological age, but that +9 years must be considered for her actual date of birth.
but be careful: this reasoning ONLY applies to Mei, it has already been confirmed that this does not apply to characters with whom a temporal rejuvenation can be speculated (mercy, tracer or widowmaker).
this is not correct reasoning. she was born human and has a birth date. and omnics also have a birth date: Zenyatta was born before the omnic crisis under the management of omnica corp and before Aurora’s awakening. Ramattra is an R-7000 Ravager model, built by Anubis at the beginning of the omnic crisis (28 years ago, in fact)