We have a Frederick that we call Fred and Freddie. I don’t think there’s anything wrong with just Fred but as someone with a hard to nickname name, I always resented that so we did Frederick for the most options.
Alfred?
Fredrick
Personally love it. We named our son Teddy and everyone always assumes it’s just a nickname for Theodore or Edward etc but we don’t care. We do also call him Fred tbh ahahah don’t know why x