It's Russian culture.
They'll try to do something "fancy" like logistic disruption by missile strikes, but eventually they just walk up and start pounding and pounding till either they're all dead or the enemy doesn't want to keep getting pounded.
As far as not having a mass murderer ordering people to their death...... I can assure you that Putin has no qualms or concerns about killing millions of his own people or others. Read up on the Battle of Grozny https://en.wikipedia.org/wiki/Battle_of_Grozny_(1999–2000)
"time lines"... "casualties"... "international public opinion"... even "Russian public opinion" doesn't matter. It only matters if your culture values one life more than that of your country. So our culture is a mix... of purple haired whiny b@tches that are offended by words, 300 pound fat bodies that dress up with glitter and tiaras to groom our children and bureaucrats that think "global warming", "racist Christian heterosexual white men" are the enemy. ...and patriotic American kids and men that are willing to put paint on their face, swim in the foam, ruck 20 miles close and kill our enemies.... Not Emma with two moms, not the affirmative action race/gender/sexual preference but men that love our country....
The Russians are screwed by culture, demographics and geography. They always want the "strong man" to lead.
Look at their history and who has led them......People that think the Russians won't go nuclear or are going to "come to their senses" are fooling themselves and are the same ones that said "Russia will NEVER invade Ukraine... cuz they're just a gas station with a 3rd world economy and nuclear weapons....."
Look how long Russia took to devastate Chechnya ... look at the size of Chechnya. It's TINY compared to Ukraine or Russia . It took over 10 YEARS to completely flatten the region.
If you want to take a look at how this is going to go... look at what the Russians did to Grozny.... that's what awaits Kiev. and no public opinions, polls, facebook memes, twitter trolls, athletic banning, ICC arrest warrants, celebrity fundraisers, James Taylor singing "You gotta friend".... nothing except Putin's death will interrupt this... and then everyone better be really worried because the man that takes over Russia isn't going to be a ballet dancer, poet, deeply thoughtful man.. but some shark that has survived the purges and murders of numerous threats to Putin. He'll have support of the armed forces and the internal security forces ..... and I can guarantee he won't be a "nice guy".
The MIGs, the armor vehicles, the tanks, the ammo, it is all simply being shipped or flown into Ukraine and Russia doesn’t have the capabilities to stop it.