Complex sentence: The Swedish victory in Oldendorf and the subsequent victory in the Battle of Pfaffenhofen on 11 August balanced the Swedish defeat in the Battle of Steinau on 10 October; overall, Swedish and Imperial forces were "on even terms" in 1633.
Split into simpler sentences: The Swedish victory in Oldendorf and the subsequent victory in the Battle of Pfaffenhofen on 11 August balanced their defeat in the Battle of Steinau on 10 October. Overall, Swedish and Imperial forces were "on even terms" in 1633.