I have two Clash Royal accounts on one game center account
Solution 1:
Try removing the app data from iCloud:
Go to Settings > General > Usage
There will be a section called iCloud with a Manage Storage option. Tapping this will load all your data stored on iCloud.
Under the Documents & Data section, check to see if your game has data saved to iCloud. If it does, simply tap on it and tap on the edit button in the top right hand corner to bring up the Delete prompt.
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