Issac was already in Savoy when he heard that Maria and her army had arrived in the Lostov region. Based on intelligence information, Maria brought along 70,000 soldiers. A little more than he expected.
However, this proved Maria's ability and competence as a Duchess and a military commander. To take care of many such soldiers was by no means an easy affair. It took more effort to keep supply lines safe and meet army needs.
Isaac couldn't help but marvel at Maria. Well, let's put that aside for now. Could say that it had fulfilled Isaac's goal with Maria's arrival. The only aggressive war will now become a decisive war.