The coalition was facing a military of 3.5 million soldiers and Russia is facing a military of 200K.
Furthermore, Russia has no interest in Western Ukraine. Their objective was Kyiv and everything east of it, as that area can be surrounded from three sides (Belarus, Crimea and Russia).
Surely you don't actually believe that such a large force existed outside the papers of a wholly untrustworthy 3rd world 'power'? The Coalition never contended with such a force.
The Iraqi 'military' was nothing more than Saddam's plaything -- a tool of domestic terror that was not fit for purpose beyond that role.
Nations cease to exist when they are presided over by dictators like Saddam Husssein; their militaries are fictional because the grunts have no true loyalty to a hollowed out State that has been captured by psychotics and megalomaniacs.
The Iraqi 'military' melted away in Iraq at first contact with the Coalition.
The Ukrainians have been receiving Western training for the last 8 years and have participated in NATO wargames; they were deemed to be very competent by NATO officials. The Iraqis were never competent.