Iraq had a "bigger army" in 1991. We saw what happened.
Russia has largely squandered their "bigger army", while the Ukrainians are using their smaller army far more effectively than anyone imagined.
Size of an army doesn't mean much when the logistics are poor, the strategy unworkable and air superiority sporadic. War today is a combined-arms operation, actually been that way for many years now. Still don't understand how Russia could have pissed away their VDV the way they did.
Russia's "bigger army" has been severely hamstrung by the old Russian/Soviet practice of denying noncommissioned officers, junior officers, and field grade officers the ability to use initiative to react with unexpected situations on the battlefield. Instead, the Russians have been forced to send generals down to Ukraine to personally ensure operations are carried out. These generals are up front, deciding what to do when subordinate units run into unexpected situations. They are acting as company and battalion commanders. Then these flag officers and colonels end up getting killed. From what little I know believe one Ukrainian general has been killed. We see the Ukes using initiative at all levels, keeping the Russians off balance. Would say they're using the US/NATO provided training rather well.
If you will, imagine Gulliver being held down by a myriad of small ropes. Russia's situation in the Ukraine is not unlike that of Gulliver.
And if Russia is having this much trouble conventionally against Ukraine, simply cannot see them defeating NATO forces conventionally. NATO trains a lot together, shares lessons learned/best practices among themselves. Their logistics are a quantum leap better.
Seriously, ol' Vlad needs to end this war. The conventional disparities between his army and Ukraine, much less NATO, grow every day.