Import multiple external audio clips to sync with video

Here is my dilemma,

I'm editing a documentary, a series of interviews. The videographer used a lapel mic for single interview subjects, direct into the camera, which is fine. However, when there were multiple subjects he routed the lapel mics into a ZOOM outboard microphone, which left me with several WAV files.

So essentially for the multiple subject shots, I have video with audio taken from the cameras onboard mic (not ideal) and multiple WAV files taken from the collective lapel mics...

What makes things more difficult is that I have already completed the edit...

Is there a standard approach to managing the syncing process? outside of going through each audio file and trying to identify the video that it corresponds to?