I provisionally have the branch of the Royles that I'd done some research on linked back to the same family as your Joseph Royle.
It's actually the family of a cousin's cousin !!! but I found them in the censuses in the Tonge area of Bolton which is just near where I live so got involved in putting a tree together.
Her ancestor was Samuel Royle who, according to the censuses was born around 1790 in Altrincham and I've tentatively linked him to a baptism at Bowdon in 1791 which would possibly make him Joseph's brother and the son of George Royle and Mary Sumner married at Bowdon in 1776.
All speculative of course but I'd be interested to see what you think.
Contact me on my home email address and I can send you a file detailing the Bolton Royle family.