Incorrect files in timeline when missing from media pool

I have various editors sending XML of timelines from PP so we can import into Resolve for Color. If a clip/file is not present in Resolves 15s media pool, R15 will just replace the clip with something else.

Why does it do this? Media offline or not present would be ideal. Replacing the clip leaves a lot of room for errors.

We could import all clips on the XML / Timeline creation, but it's linked to 50+ TB of footage and I fear that may cause some issues since we're bringing many timelines over.

Is there a workaround? Or if the media pool is already populated, will importing the clips with the XML only bring over the clips that are missing? Say an editor added something to the server that the colorist doesn't know about?

I just wanted to bump this. I had the same problem in R15 when bringing in a timeline that contained Phantom .cine files, they were in the media pool and I could view them in Resolve when I imported everything, but in the timeline R15 replaced them with different cameras / file names.