The whole thing about doctor is very simple...Everyone should choose doctor according to:
1) his ambition (promotion, title, cup winning)
2) value of players which has to be protected from injuries
Simple like that...
If you have expensive team, few NT players, young trainees, and are chasing 1st division title and/or cup title then it is logical to spend 20k on doctor. I mean, what is 20k in comparison to above mentioned?
"Da ste vi bolji narod i ja bi` bio bolji vladar!" - Knjaz Milos