I second what the other commenters have said.

There are several factors at play making conflicts almost impossible:

- A central device can be immediately synced to. For Nextcloud, it could be a server, for direct synchronization that I use (Syncthing), my phone (almost always online) is the intermediate device for all.

- You are usually online when creating accounts/password, so an sync can happen directly after a change

- And finally: How often do you actually _create_ accounts rather than just read the database? And how often do you do it on two devices in quick succession?