several lost engagements
... that dozens of Red Army soldiers switched sides and joined the Polish Army after several lost engagements during the Soviet invasion of Poland in 1939?
... that dozens of <a href="./Red_Army" id="mwCVs" rel="mw:WikiLink" title="Red Army">Red Army</a> soldiers switched sides and joined the <a class="mw-redirect" href="./Polish_Army" id="mwCVw" rel="mw:WikiLink" title="Polish Army">Polish Army</a> after <b id="mwCV0"><a href="./Battles_of_Parczew,_Jabłoń_and_Milanów" id="mwCV4" rel="mw:WikiLink" title="Battles of Parczew, Jabłoń and Milanów">several lost engagements</a></b> during the <a href="./Soviet_invasion_of_Poland" id="mwCV8" rel="mw:WikiLink" title="Soviet invasion of Poland">Soviet invasion of Poland</a> in 1939?