Guide on how to use existing audio to create podcast

Hello!

I'm new to the program and ran into a small issue.

I have audio files for me and a guest, separate audio files - but when i try to upload them I can't seem to tell podcast that they are supposed to play at the same time until I make one background. Is there a better way to do this? 

I circumvented this by exporting my audio files as one single file, but now my transcription sees it all as one speaker. Is this a software limitation or am I approaching this wrong?