>>Perhaps they were hoping that Ukraine would simply fold in the face of overwhelming force.

My reading of the tea leaves: The ex-head of the FSB is in a prison of very poor repute. Many now-ex FSB officers were fired.

I'm guessing corruption got found out, leading to prison/firing. Now, if you're a FSB officer, how do you extract rubles from your government? I’d expect that one way is to claim you are in contact with one or more pro-Russian partisan groups in Ukraine - and those groups need money...

So on top of Putin being uninformed (people afraid to tell him - or just not allowed in the room) he was being actively misinformed that there were armed groups that would rise up as soon as RF forces moved into Ukraine.

I've zero confirmation on this, but those RF paratroopers who jumped into the Kiev area had to be expecting support from somebody local — they didn’t come prepared to fight a determined foe.