I suspect the ‘interesting mix’ is because the SWs too often use him for light relief. Whereas the ‘real’ Joe (As I perceive him) is someone who often thinks deep thoughts. (Having been to Hell and back, poor man.)
He’s well contrasted with Bert, who for all his rustic poetry, is another flibbertigibbet. Joe’s connection with the land is positively mythical. In a way he’s what Tom should aspire to be - someone entirely in tune with his environment.
(Can you tell I’m avoiding a deadline??)