There are many great one's no doubt that are most likely not even on that list.
I do not have one particular preference myself with singers outside or who influences me in my songs.

I think Bob Dylan though had a certain distinction and personality about his voice.
I will take the unpopular view that he should have been on there.
But I have been weened also on acts like Foreigner and Lou Gramm would definitely deserve a spot.
He is both unique and has the pipes.

And ditto to Steve Perry and the other singers you mentioned Bob.