Hermetic names?

Why in the Atlas Games books has there been a shift from referring to magi as "X, filius of Y, follower of Z" to "X, filius Y, follower of Z?" omitting the "of" after "filius?" I'm splitting hairs, I know, but is it perhaps so that it sounds more authentically Latin? If so, it still looks incorrect to me as none of the masters' or mistresses' names appear to have been given in the genetive form, as they surely should be if you want the Latin to be accurate? Or maybe I'm wrong about that.