How to properly organize file storage for documents?

Question

Data storage

Greetings.
Synology has a share folder, say \\nas\share
There are two folders inside the share folder: "1" and "2".
Inside folder "2" there are about 100,000 subfolders. Within each subfolder there can be about 6000-10000 3rd level subfolders.
They already have documents.
If you copy files (for example, 20Mb) from \\nas\share\1\ to \\nas\share\2\folder2\folder3\ from some workstation, this may take a long time, or it may not happen at all. Copying occurs within the same gigabit network.
Is there any limit in the SMB protocol on the number of folders/subfolders?
If you go to synology via ssh, then copying occurs instantly.