eh, i wouldn't say so. when their mobiks were ignored at first they took out izium and if you think that was nothing(the rest of their gains weren't that important), think about pokrovsk aftermath - the next big stop is kramatorsk, izium allowed to cutoff the northern approach to it, but it's gone. and how did that work out? where the russians had 2 observers and a driver, ukrainians could field an entire battalion. ok that one position was pinned down by artillery, but there were 3 others in the same situation and artillery was busy elsewhere. earlier mobilisation would have prevented this loss. in fact mobilisation even now would probably put ukrainians in jeopardy. the newly raised units wouldn't be as well equipped as they should've and they'll only be active in the summer, but ukrainians have manpower shortage and even the whole "let's mass mobilise 18 years olds" scheme isn't going to yield enough to compensate to let's say a million russian troops. couple that with the fact that when the russians are fighting over 3-4 positions at the time, the sort of modern weapons ukrainians have can be spread out between them, what if it's 100 positions though?
Poland