It is fine to retreat when you are weaker and in danger of being encircled, and evacuation of the civilians in Khersan is the right thing to do, but I feel that if the Russians loses all of the territories West of the Dnipro, it is a big military blow to them. Crossing the Dnipro would be costly. If the rumors of the 60K-100K Ukrainians are true, they are indeed throwing the kitchen sink at this battle. Will see if the Russians manage to hold on to at least a beachhead West of the Dnipro before their own offensive starts.