Its not that simple ;-) I want balance (just as you), but as a CM I would pick Arthur over him every day of the week.
For example a Rabiot/Frenkie-Busquets-Arthur midfield is preferable to a Rabiot-Busquets-Frenkie midfield.
I'd pick Gravenberch over both. This dude's gravy and got talent up the ying yang!
Haven't seen him against top teams yet but by the looks of it, he plays free roaming MC - DMC for Ajax but eye test says hints he's got enough tricks to play CB, AM, LW, RW, LB, RB ... hell I'm sure he could even play goalie with a lil' training!
Right now I think he's super cheap _ like around 30 mil or so
About the Scouting Tests to determine which players would keep their focus after getting VIP unlimited access to hoes on tap, I've got the perfect solution xD: just switch our contract and salaries policies to a result based system. Fair for everyone! + if a player slacks off, his teammates would jump all over him since he'd be affecting their paychecks