Hey there @Christoffer
It doesn’t rename classess simply because they are named the same. It does that because they are classes which share a name but are not 100% identical. For example you have Container in Project n1 and you want to copy another Container in Project n2, they share a name but one has max width set to be 1000px and the other has 1200px max width. That is the reason they rename it, because it creates a conflict there. ( If it has even 1 difference it will rename it, no matter how insignificant.
Hope this resolves some of your doubts regarding copying content, cheers!