Hogan was a star long before McMahon signed him.
He was at the top of the card in every territory he worked.
He had the look, the character, and the appeal.
Vince McMahon had a vision that transcended what any other promoter had in mind.
He bought into cable TV and the MTV generation.
He took professional wrestling out of the carnivals and armories, and took it mainstream.
Hogan would’ve remained on top no matter where he went, but would have been limited by the restricted scope of the other promoters. In other words, he would be on top, but the top only went so far up.
McMahon took the business (and Hogan's potential) to new heights.
Vince would’ve tried using someone else who may or may not have faired as well as “Terry.”
Remember some of the past failures – Luger, Sid, etc.
His biggest successes since then have been “accidents” like Cena, Austin, and Rock. Vince made them stars based on the fans’ response.
Hogan was different.
Hogan is the only wrestler I can think of who Vince actively and SUCCESSFULLY pursued to make THE star.
Both men reached the heights they did as a result of the other.