You are truly blessed with a wonderful relationship and having found the man that for you is a perfect match.
You are correct that enjoying sex with black men or men with larger or smaller endowments does not have to mean that your husband is lacking in any way, it's just enjoying the variety that may be available to you if you have a loving mate who enjoys seeing you happy and gives you the freedom to enjoy yourself.
There is a misconception that all cuckold relationships must have the dynamic of a "wimpy" husband which is completely untrue. Many men, who willingly submit themselves to their wives pleasure, are strong, "manly" men, who no one would ever consider being wimps, beta or submissive in any way. They just enjoy a submission dynamic with their wives.
In your case, cuckolding isn't really even the appropriate term as your husband also has his playmates, so yours would fall more into an open, swinger type of relationship, which along with the "Hot Wife" dynamic, may be the preferred situations for most couples who are adventurous spirits sexually instead of cuckolding.
Just goes to show there's more than one way to enjoy life.