Doctor reduces the likelihood of injuries, you can do with a minimum doctor if you don't have key trainees nor very high salary players.
A Trainer is only useful if you have trainees and if you don't have high potential trainees you should stick to the cheapest lvl 4 trainer you can find (fee+salary), as they are the most cost effective.
Most people think the PR is useless (i.e. you will spend more money on his salary than he you will make thanks to him in extra revenues) and he probably is unless you have a large arena or high merchandising which is not the case for new teams.
Note that all of the above primary staff have a specialty that increases their usefulness and whose effect is not proportional to the level of the staff (Massage specialty for lvl 2 and lvl 7 doctors is the same). I would not bother with secondary staff right now, although the youth trainer and the psychologist are pretty useful depending on the situation.
For new teams I would advise to invest everything in the Arena. Then pick up trainees after the draft: you can probably find Superstar and Perennial Allstar potential quite cheap as there is an abundance of 18yo and 19yo players being transfer listed after the draft. After you have your trainees get a Trainer (lvl 4 cheap), Youth Trainer (lvl 4 or 5 cheap) and maybe a doctor. Train while you you build your arena and round the roster with better players to replace the ones you were given.
Last edited by Lemonshine at 7/9/2019 7:11:51 AM