In domestic warfare, you only need soldiers and weapons, and logistics supplies can be provided by local governments nearby. But when sending troops overseas, a large number of draft horses and wagons are a hard requirement; besides, many military craftsmen are also needed.
Previously, Russia lost tens of thousands of horses in the expedition to India, as well as almost all of its accompanying vehicles, so at this moment, the army that can be dispatched to Europe numbers just around 60,000.
It's necessary to wait until the vehicles and supplies from Moscow, Novgorod, and other places are transferred to the West before increasing troop strength further.
Suvorov did not always travel with his main army but, after entering Little Poland, headed to Vienna alone with his guards.
