Re: Looking to see who can be centerfield
Hamilton is solid in center. I think you're selling him short. I think if you have Hamilton in center and Bruce in right, you have a pretty good start to a good defensive outfield.
As for the too-many-lefties argument. I agree that the problem isn't the lefties. It's the righties. The Reds went into this season counting on Encarnacion as the right-handed bat in the middle of the lineup. He flopped spectacularly. Ross fell off big-time. Gonzalez was OK, but has been out of the lineup for long stretches. One of the reasons for the second-half upswing by the offense was the play of Keppinger and Hopper, who at least gave them some timely hits against left-handers.
So the solution isn't necessarily subtracting lefties. It's adding righties who can balance the lineup. Only Phillips qualifies. I will say that I think you're discounting the problems against lefties a little too cavalierly. You can use career numbers, but Dunn has been undeniably bad against left-handers this season. Is that just a bad year, or indicative of a bigger problem? I don't know, but I wouldn't want to build a team for next year assuming a big turnaround.
Finally, let me just say that I hope every available resource this offseason is used to acquire pitching. Center field is the least of my worries.