[Git] How to separate large project ?

Hello!


I would like to separate a git project into smaller repositories:
> Core + subproject1
> Core + subproject 2
>...

Core being in its own repository and i would like it to not get any bigger.
Each subprojects would have their own repo and cant include Core cause they are already big themselves, and on the local work machine i could end up with multiple copies of Core + 1 or more subprojects

i have read many bad stuff about git submodule and some suggest using subtree, but subtree will not help keeping the Core part small right ?
Also thinking about cloning my Core project and add a subfolder where subprojects would be to gitignore and put other repositories inside, is that possible ?

Thanks for your help!

Julien.