<< To "sync" these 4 tracks [4105 (Tenor Hi), RT 4106 (Tenor Lo), RT 4107 (Baritone) and 4108 (Bass) ] to a harmonic choir. >>

Yes. Use the RealTrack Medley Maker.
Highlight a blank track for the choir
Open the Track Sections and Dialog Page (T+<enter>)
Click on Medley Button
Input the RealTrack numbers onto the Medley boxes
Pan and adjust the levels so the performance sounds like you want it to
OK out and the harmonic choir should play correctly

Attached Files (Click to download or enlarge) (Only available when you are logged in)
Medley.png (65.28 KB, 53 downloads)
Medley Maker Page with vocals.png (21.14 KB, 53 downloads)
RealTrack Medley Maker Page with vocals added.

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