YOU need to check your sources ....russia have been taking as bad a hits as Ukraine have and those figures are ridiculous in actual fact it is Ukraine with troops in reserve not russia - russia continue to be wasteful of their men and seems to me a current strategy by Ukraine is to stretch the very long russian defence line as much as possible - (bridgeheads over the Dnipro for instance ...)
and yes ...Ukraine have reached the first line of defense now near Urozhaine and Robotyne the advances have been ,admittedly painfully slow but are happening