Essential Graphics - Content Place Holder problem when inserting a Sequence in Premiere

Hello,
I mad a few picture-in-picture template in after effects for my colleagues using premiere, so that they can't mess up size and positioning.
My content placehoder are compositions: a 16:9 (1920x1080), 9:16 (1080x1920) and a 1:1 (1920x1920).
I was about to instruct my colleagues by saying that probably is better if they edit and put toghether the content for the window in their main sequence so they can sync it with the video behind it (normally an interview) and the nest everything and drag the nested sequence over the content place holder in the essential graphics panel. 
The problem I noticed is that while if you just drag an image or video, that single file is fitted inside the composition that continues to be in the right dimension and proportion, if you drag a composition the composition made in premiere completely substitute the place holder comp from After Effects and so proportion and dimensions change.

The easiest solution would be to remember my colleagues to always create a sequence with the right resolution, but my aim is to create something bulletproof so that even if my colleagues try intentionally, they can't mess it up.

Is this a bug or a normal behavior, is there a way (a part from rendering the content of the sequence) to make so that a sequence from premiere is treated exactly as a single file(image/video) when dragged into the essential graphic placeholder ?