Another source where he mentions to follow quran and mentions sunnahHe never said that and nor do you have any way of proving that he did. His emphasis was on only the Quran and Quran alone.
And all sects are against the Quran and involved in shirk. Be it Sunni, Shia, Brelvi, Deobandi, Jaffriyya, Ahle Sunna etc etc etc
Source: https://d1.islamhouse.com/data/en/ih_articles/single2/en_Prophet_Muhammad_Last_Sermon.pdf