I think they only true thing in the title, IMHO, is the word 'unlikely'. Garth drew people of all ages, didn't rip the sleeves off his concert attire, and never postured himself as a 'sex symbol'. Plus I've can't recall Garth giving interviews on his sex life or loosing his virginity and such. He's conducted himself with a great deal of class.
Garth simply wrote and chose great music to perform and let the music do the talking. Kenny has an easy going way and I've enjoyed quite a few of his songs. But to me, Kenny is like cotton candy, pleasantly enjoyable occasionally; Garth is a great meal with family to be enjoyed often.
Since Garth is still heavily played, I don't feel his shoes are up for the filling. Kenny is Kenny; he shouldn't have to be the 'next' anyone.
"Grace is when God gives us what we don't deserve and mercy is when God doesn't give us what we do deserve" - Dan Roberts