How can I change the order and number of clips whose cutting is tied to the beats in the music?

Question

Apple Final Cut

I want to take a certain composition and place clips on it so that their change is tied to the beats of the music. I dragged the audio to the timeline, threw some kind of dummy clip on top of it and stretched it along the length of the audio. Then, listening to the audio, I cut this dummy. I'm starting to add my videos with Replace from Start to the dummy clips. Then it turns out that either my videos are longer than the length of the audio, or less, and I need to adjust the duration of my videos. How to be in this situation? For example, if I add a video to a certain clip, the rest will shift and I will lose the link to the audio. How do you change the length and order of video clips while staying in sync with the music?