Folks, keep in mind 40 k is less than a divisional slice in Western parlance.

The Western politicians who are raising alarms about Russian 'troops concentrations' have no reason to downplay their extent by counting combat troops or troops in manoeuvre formations only. I strongly suppose they're counting all of them.

And 40k army troops aren't many. Seriously, that's about the size of the Bulgarian army.

20k, 40k, 100k - the figures don't really matter. What matters is whether and how quickly the current crew in Kiev gets its act together and gets loyal armed forces under its control. They may need to purge ethnic Russians from their army and maybe join two manoeuvre formations into one to get enough loyal troops, intact equipment and spares, and this (or other measures to the same end) takes time.
It doesn't take 12_years_for_the_mayor_of_Kabul time, but it takes some time - probably months.