Developmentally, Reddick is leaps and bounds ahead of where Murphy was at this age. Reddick was in AA at age 22 and got a cup of coffee in the majors, Murphy was in A at age 23. Reddick was generally a year or two younger than Murphy at the same level and his OPS in the minors was still over .100 points higher than Murphy.
I think Reddick will hit for power because he has at every level of his development. I'd be surprised if he's not able to be a 20+ HR, .500 SLG guy. He also more of a contact hitter that people give him credit for, he was rushed through the minors and still hit .278. The wild card will be his patience. He walking at a rate this year that's almost twice as much as his previous walk totals. If he can keep that up, .280/.360/.550 is well within reach. If he goes back to being overaggressive, he's probably more like a .275/.350/.500 hitter.