Convert an original audio to AI voice-over and sync it to the actions in the video in one go?

The course I am working on has 10 different videos. The voice-over has been done by a colleague, who would like it to be replaced with an AI voice-over.

The challenge:

The voice-over is done in German, which I do not understand that well. Even if I export the closed captions of the original voice over, they get downloaded as individual audio scripts with time stamps. So I will have to generate AI voice-over for each audio script. (These are 10 different videos ranging from 5 – 15 mins long. You can only imagine how tedious it could turn out to be) Even if I do that I wouldn’t know for sure if these individual AI generated audio clips would align themselves exactly to what is being done on the screen. I need a way to ensure that it happens.  

My goal is to get the AI voice-over done for these videos in one go and get them synced perfectly. Is there a workaround for this?