In the XVIIth century sentence "Sono cosi diversi i sentieri per li quali s’incamina al possesso del buono nella Pittura," how would you translate "s’incamina al possesso del buono nella Pittura"? Possess the good in painting isn't right. Master excellence in painting?
First your sentence is incomplete, I'll do my best to guess how it should continue (because the translation might depend on that). I think
The paths to reach mastery in Painting are so different [...]
is a good free translation. Depending on how the sentence continues you could also say
There are so many different paths towards skill in Painting [...]
If you want a more strict translation you could say
The paths through whom one can set forth to own the skill in Painting are so different [...]
(yes, it sounds a bit clunky in English).