Zelensky sacks Ukraine's commander-in-chief Valerii Zaluzhnyi

That's a rather remarkable leap to make. I hope he's right about it. There is no doubt that the existing leadership was unexpectedly good and staved off a widely-expected loss.

Having accomplished that, it's reasonable that a different phase would require a different approach. They do seem to have reached something of a stalemate, and maybe different tactics can break that. But hoo boy is that a big gamble to take, when there is also the possibility of making it much, much worse if you're wrong.