Cutting videos into individual clips - loss of quality? I have over 100 videos, each around 5-10 minutes long. From each video, I might only need two or three clips that last maybe 10 seconds at most. I want to create a montage out of all these videos using only small snippets from each video.

This is the first time I've ever done something like this. What I planned to do was to extract each clip from their respective video and then use that clip for the montage. This is mostly to save space and to avoid having a huge project file with many different cut up videos, as I barely need even 5% of all the videos I have.

However, I'm concerned the quality will be lessened when I cut up the videos like that first. Is that in general a valid concern if all you're doing is cutting up videos with no editing? Or is that handled differently by different video editors?

(I'm using Hitfilm Express btw.)
Theoretically, encoding will always reduce the video's quality although it may not be noticeable. And it is not necessary to encode (use codec) in video trimming. But, if your video editor (Hitfilm Express) uses a codec to encode as default and does not have an option to do video trimming without using codec or encoding, the video quality will be reduced.