Many of the admirable traits of the WW2 Russian Army. doggedness on defense, extreme national zealotry, an indomitable toughness, and a willingness to make extreme self scarifies also are traits of the Ukrainians. After all they were part of that WW2 Russian army.
It may be foolish of us to underestimate the power of the Russia Army but by the same token it very foolish to underestimate the power of the Ukrainian Army.
The Ukrainians have a long and bitter history with Russia.
With in living memory some 5 million Ukrainian were deliberately starved to death by Stalin's Russian government. The West largely ignored or downplayed the Holodomor. For the Ukrainians it is an ever presents dark memory.
And at least the Defense Minister of Ukraine is a Man, unlike the wussy Western European countries.