It comes down to a personal opinion
It's impossible to rank them.IMO,there are too many players that can be ranked as the best player ever.They all play different positions,have different roles,skill sets,abilities and so on.
But they are at the end,judged based on their performances in the big games,winning,career resumes.It's also a key factor on what you base your argument on.At the end,it's a matter of personal opinion.
I decided once,that not one but dozens of players can be praised as the greatest ever overall or in some category but it's just what do you think on them.So when i say,Player A is the best in something,i always use arguably
So,it's the finest to rank them on their respective positions with players of those spots.And for the G.O.A.T debate,it's only matter of opinion