All I can say is: since the 2014 Crimea fiasco, the Ukrainians have been trained by a top tier force, to SPECIFICALLY fight the exact type of conflict they are now involved in, against this specific adversary, their weapons, and their tactics. Since 2014, Ukraine has bolstered its military strength to take advantage of the training at a service-wide level. I don’t think Russia has had this same approach as Ukraine has, since 2014.
