I always try to put my highest RRF player in Center Field, but almost must discliam that I rarely use D fielders, and never use D- fielders. Not to overly complicate things (fielding in SIM is complicated), but you also need to consider your pitching staff's composition. If you're using dead ball guys, I think it's important to have high Fielding position players. When using more modern day pitchers, you can sacrifice some fielding.
In general, and only as a rule of thumb, I've found it's best to have good field/high range players in CF. I will sacrifice some field for range there is necessary, e.g. take a C/A+ guy over a B/B+ guy in center). I often use average to less-than-average range in LF and RF (i.e. D+, C-, C).
In addition, TJ's post immediatley above is how I would allign that specific corps of OFs.