You could probably use Fifa 10-21 ratings as an yard stick (or this might actually be generational talents/elite, a notch above World Class). If you want to distinguish between WC and GT you might say 84-86 for wing backs is WC and 87+ is GT, 87-89 is WC for GK and 90+ is GT.
Each players best rating, most had longevity and some where one-two season wonders. There might be several players in one position that are rated as world class at a particular moment of time and there might be none.
GK - Neuer (92), Oblak (91), De Gea (91), Ter Stegen (90), Allison (90), Casillas (90)
CB -
LB/RB - Ramos (90), Maicon (89), Lahm (88), Dani Alves (88), Marcelo (88), Kimmich (88*cdm), Alba 87, TAA 87, Robertson 87
CDM/CM -
COM -
LW -
RW -
CF -