A lot would depend on who the club, whether it stayed as Everton or rebranded itself Liverpool FC, brought in. If they fully followed the EFC path from 1878 until now, then I don't think they would have much more success than what they have had, although not making decisions based on the jealousy of what we were doing might have changed things.
The biggest influence on our direction as a club was Shanks being appointed. He started the ball rolling and it was his assistant Bob would brought the huge success of the 70's and 80's and it was a player Bob signed, King Kenny, who carried that on until he had to stop.
The club could have followed a similar path to us, but in 1991, chose not to have appointed Souness - that would have changed things, both for us and for Man Utd...