Since your cameras share timecode, I would create a multi-camera source sequence with your subclips and the other camera angles, then create subsequences based on the subclips. You’ll then have a multi-camera source sequence for each subsequence, with both cameras in it.
- Select the other camera angles and your subclips.
- Choose Clip > Create Multi-Camera Source Sequence.
- Set Synchronize Point to Timecode.
- Set the audio Sequence Settings to All Cameras.
- Right-click the multi-camera source sequence and choose Open in Timeline.
- Move all your subclips onto the same track, and delete any empty tracks.
- Step through the timeline. When you reach a subclip, select it.
- Mark In and Out around the selection (/), then Deselect All (Shift + Cmd/Ctrl + A).
- Choose Sequence > Make Subsequence (Shift+U).
- To turn the subsequence into a multi-camera source sequence, load it in the Source Monitor, right-click, and choose Multi-Camera > Enable.
In the future, rather than using subclips, I recommend creating multi-camera source sequences and making subsequences directly from those.