"russia are needing to to pull troops from the third line to try and stop the Ukrainian advance now"
That's been the reason for the continual attacks over such a long front line. Ukraine is making the Russians use up all of their mobile call up units to plug gaps. Brings them out of hiding and puts them on front lines strung out over a large distance.
Main force of Ukrainian counter attack yet to be deployed. They'll wait until Russia has used it's reserves, and to see the most fragile part of the lines, before committing to a specific area.
