How to swap in video clips with different durations into the same in and out animated areas

You might want to consider creating animation presets for your animations. About 90% of the animation presets use a layer's in and out point instead of keyframes to create the animations. When an animation preset uses keyframes, the first keyframe in the preset is applied at the current time of the composition. Most of my presets are fairly complicated.

If you could explain your design goals and describe what the animation does, we could help you come up with a solution that does not involve replacing clips. We might be able to help you streamline the entire process.

So,  animation after the footage would have to be adjusted for each clip duration?  Each footage clip has a different duration and out-point.  Is there a way to use a responsive design approach?

If you open the footage panel by double-clicking the footage in the Project panel, You can set an in-point for the asset. You can then select the clip you want to swap in the timeline, select the trimmed clip in the Project panel, hold down the Alt/Option key, and drag the new layer to the timeline to swap the clips. The in-point you set in the Footage Panel will match the start of the original footage.