If Google getting your data is a concern, then you shouldn't be using these apps at all right now, if you're going to have Play Services installed alongside them with network access. It doesn't matter if you take away their network permissions, if Play Services is there and has access to the internet (for notifications), then they can just send the data through Play Services.
I wouldn't necessarily discount the possibly that a non-Google app that has Google libraries in it could have been designed to communicate woth Google apps for this kind of data exchange either. Then you wouldn't be safe from that even if you didn't have Play Services, you'd need to thoroughly vet every app you use to make sure they don't include any Google libraries.
You could have some elaborate setup to check and verify that neither Play Services nor any of your other apps are sending data on behalf of your Google apps, but that doesn't guarantee you that they couldn't statt doing it in the future.
If you don't care that much, then just use the apps and don't worry about it too much. Otherwise you probably want to wait until app communication scopes, which should allow you to prevent apps from communicating with and sending data to other apps. The Network permission is a false sense of privacy right now in a lot of cases.