I don't agree, everything I see tells me over confidence and arrogance lead Putin to believe this would be a walk over and the reason the Russian military has come unstuck starts with arrogance and extends to corruption.
The reason Russian troops are not that good isn't because Russia can't train a professional army but rather money is being drained from the system at every step, the reason Russia can't equip it's troops with modern weaponry isn't because it can't make them but because politicians, arms manufacturing executives, base commanders, logistics personnel are all skimming everything they can get their grubby hands on off the top.
Hell I am prepared to bet that the much vaunted 2000 combat aircraft Russian air force doesn't exist because half it's aircraft and facilities have been sold for a handful of hookers and a crate of vodka.
Basically Russia is nothing more than nuclear armed joke and I wouldn't be surprised if half it's warheads didn't exist either.
Russia (with a population of only 142 million people ) would be better without a professional army ( in fact half of its manpower are conscripts ) but with a stronger army with less professionals and more conscripts .
Its manpower is only some 1,1 million men ( figures do diverge )and half of its active forces are in Ukraine .It needs more than the double to protect its borders .
Professionalization means less boots on the ground, not only for Russia ,but also for the West, with the inevitable negative results .
There is corruption in the Russian army, but with less corruption, the result would be the same .
Russia needs more quantity, not more quality . So do Germany, US, UK,Belgium, etc .
Due to its shortage of infantry ,Russia was forced to use tanks, too many of them ,and in a wrong strategic and tactical employment .
About the confidence and arrogance: the Russians convinced themselves that there would be a miracle,because they knew that they could only win if there was a miracle .
The conclusion was : we will win,because we must win .
In June 1941 the attitude of the Wehrmacht was the same .The USSR was potentially much stronger than Germany and if it had the time,it would defeat Germany .
Ukraine is potentially much stronger than Russia,and if it has the time, it will defeat Russia .
200000 Russians are fighting against 40 million Ukrainians ,and the outcome is already a public secret .