Going out on a limb here... he has obviously always been compelled to write songs, and the story-telling style hasn't changed 'too' much. So without the mid 80s success I think there'd have been a continued DS with an ever changing lineup.
As for no Sultans success, he doesn't seem to have confidence or 'giving up' issues. This is the man that dictated to Chet what type of album they'd make, and sang Elvis next to Scotty Moore. Apart from maybe 'Twisting' has never wrote a song to be a hit, simply to have a hit. I think he'd still have endured, and carried on doing his guitar/songwriting 'thing'. If not sultans, another song breakout was inevitable with this kind of talent, one day. And the songwriting and guitar style is the key. Tommy Emmanuel is an example of incredible talent but no Great song, so very few care, the man still has a great day job though
