Unless you don't plan on using any Google apps with network access, I argue 2-3 profiles is the minimum to get what I consider to be a noticeable privacy advantage due to inter-process communication (IPC) between Google apps.
Your main profile is where you keep all your day to day apps. A second profile is for using Google apps that require network access. If you're comfortable with using the Aurora store, then you can limit this to two profiles, making your main profile the owner profile. Otherwise, for more security, dedicate the owner profile solely to installing apps from the play store using a throwaway Google account with an always on VPN and push those installs to your other profiles.
The point of separating the Google apps is so you can utilize some Google apps on your main profile with revoked network permissions while still not worrying about them communicating back to Google through other installed Google apps via IPCs. For me, I'm very concerned about Google potentially logging my key strokes on gboard, both from a privacy and security standpoint. On stock, I had to disable Gboard and use an open source alternative instead. With Graphene, I get the option.
Other useful no-network google apps for me include Google Photos (offline), Pixel Camera, Google's Text to Speech, and Google Voice Typing. Google Photos is the only way to get some of the pixel exclusive editing tools. And similarly, google's text to speech and voice typing are light years better than the alternatives. Note, some of these apps need temporary network permission to download content and features so they can be used locally, after which, revoke the permission. I'd recommend doing this while connected to a VPN.
Install sandboxed play services on your main profile if you need it such as for app compatibility or reliable and battery efficient push notifications. Minimize permissions to each of the sandboxed google services. Since you isolated the apps with the most demanding permissions to their own profile, you should be able to put a tight leash on the play services on your main profile.
Some apps provide their own service to provide push notifications if you don't have play services installed. Some don't, which means no notifications from those apps (cough Proton). And some apps do it so inefficiently that play services will actually save your battery life in comparison (cough Signal).
Your Google user profile is a good place for any app that requires a logged in Google account or a Google app that requires network access. This is where I'd install Google Maps and Google Assistant for hands free navigation. Many Google apps need the main Google app installed so don't forget that.
If you use WhatsApp, they restricted backups to Google Drive backups (which can be encrypted). But this means you need to install WhatsApp on gour google user profile with Google drive installed and logged in if you want a reliable backup. Secret hack, you can also install WhatsApp on your main profile as a linked device so you don't have to keep switching back and forth, just scan a copy of the QR code. I found everything works minus backups obviously. This doesn't even need play services.
Another nice part about this setup is that you can turn off the Google user profile when not in use to further minimize background google activity and to save battery life.
Even if you still use Google apps on the regular, you should still be able to access most them in other ways on your main account. For example, using k-9 mail to access Gmail. Many Google apps also have high quality progressive web apps (PWA) that you can add to your home screen from the browser. These are hopefully enough to make switching to the Google Profile uncommon enough that it remains turned off most of the time.
For me, I'm mostly just going to it for google maps navigation (PWA doesn't support navigation) and to make sure WhatsApp did a backup once in awhile. Like no joke, you can even start a call from the Google Voice PWA. You won't get push notifications, but you can have it forward Messages to your Gmail account. Don't underestimate the PWAs.
If you have banking apps, you can decide where to put them. Some people make a whole new profile. My only recommendation is to just use their website on vanadium instead of the downloading apps. Besides mobile check deposit, which i rarely need to do, I can do everything else on my banks' mobile websites.