I think the concern is less the missiles and more the artillery, which can be fairly inaccurate at times when the wrong numbers get punched in.
To my knowledge the ukrainian doctrine has not changed much at all and still has the soviet structure. They really didn’t have a military to speak of until 2014 happened too, which is why they had the fascist militias fighting the front of the war vs the separatists for so long. Nato have been changing their structure and tactics through external training of specific batallions but I’m not sure we have much idea of whether those are performing any better. Given how poorly the ukrainian offensive went I’m leaning towards nato tactics and structure being completely unprepared for an artillery war and trench battle of this kind. It’s closer to ww1 than anything with heavily dug in lines that spend most of their time looking out at a no man’s land.
I don’t think Russia taking more land will end it. Russia will continue this war until they take Odessa and Mykolaiv to landlock Ukraine. At that point it loses all sovereignty as it will have to negotiate for port usage to export grain. So to be honest unless negotiations open up between the US and RU I expect this to last 1-2 more years at the current pace, especially if every major city takes as long as Bakhmut.