If you are using a Panasonic GH3/4/5 to record your long-form video, the first thing you want to do is to create a consolidated ProRes422 master file out of the numerous clips recorded by the camera. Once you have done this and have imported your master file into your working library, then you are ready to import the audio tracks from the Tascam DR-70 (or other audio recorder like the Zoom H6) and synchronize them with the video clip.
The following video shows you how relatively easy it is to synchronize a single video clip with matching audio tracks. And yes, less than a minute into this my wife texts me to request that I make my famous twice-fried bistro french fries with dinner.
synchronizing audio and video from Loyola DOHS on Vimeo.