i'm guessing that people have different interpretations of Sikhi and the standard of Rehit!! like Budha Dal Rehit is quite millitant and has been kept the same for loadza years and hasnt changed, but i think that other Maryada's have been kept the same and have not changed that much, yet it is the way people like to interpret them and how some are lenient on some aspects of Sikhi than on other parts!
Like Taksal focuses a lot on the pronunciation of Gurbani and how to say Baniaa properly, because they believe that this will better them!! yet Budha Dal Nihangs also focus on reciting Shud Baniaa and yet they also focus on the martial side of Sikhi, trying to preserve arts (vidiya) as in Shaster Vidiya, Archery, Horse-riding etc.
also, the Gutka that different Sikhs recite from differ too, which also impacts on their maryada.
hope this helped,
Bhul Chuk Maaf!!