They don't have the missiles, and they're using Chinese, Iranian and North Korean supply there.
What they are apparently outgunning NATO on is artillery shell production. None of our countries have switched to wartime production, while Russia has, at least in some degree?
Moreover, if they have commanders that survive now, those commanders will be accustomed to drone warfare and drone based artillery spotting with firsthand experience and ours aren't.
If would still be a slaughter, but a lot of people would die on our side in the process. Not to mention China would absolutely start some shit too. Maybe Modi too, since he's more on his own than with NATO or Russia.