Why use of EZGIF to overlay 2 gifs is not recommended?

Hello,

1st approach:

Add overlay animated GIF on a second animated GIF:

This will not work just simply because it will only show the first frame of a GIF and then it is a static animated GIF.

2nd approach:

Split 2 GIFs into frames and overlay frame by frame:

This will not also work just because you will not place it at the exact position unless you will get it from the first image.

And even this would not work.
Let's say the first frame long is 60 seconds while the second GIF frame is 10 GIF then overlay by such a method or even getting the overlayed image and then splitting and placing frames will not work exactly as happened.

Then if you overlay the animated logo of the company on a GIF then EZGIF will not be a good solution but if it is the static image it would work.