it actually wasn't the turkish-backed terrorist group that seized the capital from the north, it was an american-backed group that came in from the south, and the russians reacted by entirely bailing, apparently to avoid conflict with the us. what's worth noting is that the americans got there first with intent. they wanted to be in control, clearly, and wanted to take that away from the turks, who had to step back.
it follows that while it is the case that the turkish backed group, as an arm of a nato ally, has been installed as a puppet ruler, it is actually american boots on the ground that are in charge of the process. i don't know exact details, but i'd imagine they went for the palaces and the airports.
the israelis also came in from the south and the picture you put together is that the israelis and americans were trying to block the islamists from getting past a certain choke point, which is actually substantively to the north of damascus.
once the russians realized the americans went in, they flew assad to russia and stopped bombing the islamists. that was probably smart.
so, keep this in mind going forward: while it looks like the americans want to put the islamists in charge, which is exactly what happened in afghanistan, this doesn't actually appear to have been a turkish coup, after all. it's an american coup, and there are pentagon spooks sitting in syria right now calling the actual shots.
the russians and remnant syria forces might have been able to push back against turkish backed rebels, but they are not playing games with a direct american takeover. the americans came out of the desert. israel pushed in from the south. turkey came in from the north. the kurds got cut out.
this is consequently starting to look like syria no longer exists, and is going to get cut up, like libya.