Your Patron Saint is the Saint whose name you adopt at baptism, not everything requires "check with Spiritual Father" some things are just known, usually by the "cradles" because it has been part of their culture for hundreds and hundreds of years ... knowledge as old and as timeless as the Church Fathers with no disrespect intended by me by the way I said it.
We inherit some of the "properties" of the name and also the characteristics of the Saint who sanctifies that name.
This does not prohibit us from assuming "honourary" Patron saints ... some cultures adopt a Patron for the family household (usually this custom is to assume as Patron the Saint whose name the "Father" of the house holds) ... other cultures assume a secondary Patron Saint each year.
This honourary title of Patron should be discussed with your Spiritual Father, I guess but you would not be breaking any Canons and it certainly does not harm anyone to honour a Saint!
However, our true Patron is the Saint whose name we adopt because we "inherit" spiritual tendencies from.