Accepted military doctrine says that an attacker should have a 3-1 advantage over a defending force.
The Ukrainians had a 3-1 advantage over the attacking Russians & the Luhansk/Donetsk militias.
I'd say that the Western militaries have some doctrinal revisions to attend to.
Given the new technologies , almost all military doctrines and tactics need to be questioned and revised. Armored fighting vehicles and naval surface combatants are now largely obsolete. Some hard lessons were appreciated by some who carefully observed the Ukraine war and the Azerbagani-Armenian conflict. If history is a guide, very much doubt the current crop of battleship admirals and cavalry generals patrolling the halls of the Pentagon have taken notice.
No kidding! The Russians & their allies are apparently firing 60,000 artillery rounds all day, every day, without pause.
Analysts are tearing themselves away from abstruse models of SEAD ops. Instead they're wondering how the Russians got to fight this war with an infinite ammo cheat.