The irony is that, unlike east of Kharkiv, the Russians in Kherson appear to be withdrawing in relatively good order (probably because Russia sent many of its best troops here).
However, unlike east of Kharkiv, the Russians in Kherson are rapidly running out of areas they can withdraw to, because of the severed Dnipro crossings.
Up until now, Ukraine has only been able to hit those crossings with expensive long-range munitions eg HIMARS rockets. If those crossings come within easy howitzer range, Ukraine can basically keep them under bombardment 24/7.
Rapidly approaching winter is a very, very bad time to have your supply lines cut. And yet withdrawing across the river means many of Russias best units which were deployed to Kherson could end up losing most of their equipment. Decisions, decisions...
Maybe the question "command and control breakdown vs. lack of reserves and impossible commands from Moscow?" is academic, since there is always some way to move people and equipment around to cause the other guy trouble.
I'd be more inclined to consider it an academic question because it is not mutually exclusive. 'All of the above' is the answer I would tick for the overall Russian campaign.