iCloud
Can I have two iPhones with the same Apple ID and iCloud family sharing but different data?
iPhone X, iOS 13
Apple’s Worldwide Developers Conference to kick off June 10 at 10 a.m. PDT with Keynote address
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
Can I have two iPhones with the same Apple ID and iCloud family sharing but different data?
iPhone X, iOS 13
If the iPhone's are using the same Apple ID, then iCloud Family Sharing is not applicable since the Apple ID already has access to the iCloud Storage it has bought. There is no point in sharing something it can already access on its own.
If you want to Family Share iCloud Storage, then each iPhone needs its own Apple ID for iCloud.
If you want to keep data separate such as contacts, photos, calendar etc... then each iPhone needs its own Apple ID.
Family Sharing works across different Apple IDs. If the devices are all using the same Apple ID, then it defeats the purpose of Family Sharing.
iCloud