How could you delete iCloud in a phone if they are too many?

One Apple will have only one iCloud.

1. When you create an Apple ID iCloud is by default created and 5GB space is allocated using the same Apple ID credentials.
2. As soon as you log in with an Apple ID an iCloud associated with it is enabled on your device and few apps are enabled by default. You may choose to disable any of these apps under Apple ID.
3. Tap Settings > [your name], then select iCloud. 
4. Turn off Mail, Contacts, Calendars, and Reminders, Notes, Messages, Safari, Stocks, Health, Wallet, Game Center, Home, Siri, Keychain, iCloud Backup & iCloud Drive etc.

Watch the GIF below