Turkey stopped supporting ISIS a long time ago. They're now directly fighting the Kurdish SDF, the last remaining American proxy in the region. They agreed to cooperate with Assad long before the Saudis did.You seem to be unable to assess these countries on their whole history except for the last 12 months.
If you think that Saudi Arabia is now a Chinese ally and can't return to a new republican president of the US then I'm not sure what to say except you might get a bad surprise once Trump is back. They haven't stopped military cooperation with the US, have they? They want to have a way back, just in case.
Not all the GCC members followed Saudi Arabia in ending and then normalising relations with Iran. Countries like Kuwait, Bahrain and Oman also don't really matter and Qatar is not friendly with the Saudis. Egypt is really the only major country. Syria and Yemen were obviously part of the deal with Iran. The Saudis have some sway in the Arab league, but most countries have already accepted that Assad has won and they all want to get rid of the refugees.
The Saudis also don't lead the Arab world in their response to Israel. Many countries signed the Abraham accords while the Saudis watched.
I don't understand why you are surprised that the Saudi intervention in Yemen ends when the Saudi troops go home?
He's widely regarded as a slightly crazy person who occasionally makes extreme statements. But the rhetoric doesn't matter as much as the actions. And you don't need to walk anything back when you're a literal NATO member
Syria is an example of how Turkish objectives are directly clashing with Russia and probably China. I think we can agree that Assad is the best option for Syria. Why do you think that the next Turkish foreign policy adventure will be more positive?
You have to be very careful when reading media about US allies. The western media will take and amplify the myths these countries have about themselves.
China brought Iran and Saudi Arabia, bringing together Qataris, Turks, Egyptians and other Arab regimes is much easier. They all have a common enemy.