"In preparing for battle I have always found that plans are useless, but planning is indispensable". - Dwight D. EisenhowerThey made many mistakes but they still reached Kiev. Military operations are inherently unpredictable but Russia didn't seem to have planned this very well.
Anyway, Russia's military is too big and too strong for it to lose against Ukraine, but that means the conflict will cause them more casualties and it will most probably get prolonged