Information Please- Surname Rules

[Talka]

It seems that when I come across a child born out of wedlock his/her name includes the natural father's surname as a middle name.
In one instance it seems that child dropped his mother's surname in favor of his father's name when he got married.  In the era between 1750-1800 would that have been allowed or usual in the same community?  Did it depend on the current clergy or whether the natural parents were still living? 
Thanks for your time and assistance.

[KGarrad]

Under English Law, it has always been permitted for a person to call themselves anything they like
Just as long as there is no intention to deceive or defraud.

[Talka]

Thanks very much!

[groom]

It isn't that unusual you will find people using different surnames for lots of different reasons. Often a child will take a stepfather's name during childhood and revert back to their birth name as an adult. Or they will suddenly start using a stepfather's name and keep that. Others as in your example use a father's name even though that wasn't how they were registered.

I have someone who used a step grandfather's name as he was bought up in his family - he kept that name all his life and his descendants are called that. Another changed his name in order to inherit money - it was in the terms of the will.

[Talka]

Thanks.
My dilemma is that it  appears to be a back-and-forth situation.  I could be looking at one man or two- Richard Messenger Tuckey or Richard Messenger, both born circa 1744, both married to an Elizabeth, both with children baptized in Boddington  but have not found  records to eliminate the possibility that they are one man.   Will keep looking.   
Thanks again!