That's already early Rennaissance, stabding mercenary formations started to show up around that time. Feudal armies tended to be passants being called to arms centered around some highly trained knights and professionals. The Mongols were a standing professional army, something that played an important role during their campaigns.

I don’t think there is agreement to when the Middle Ages ended and the Renaissance started, but 1458 could easily fit into both. That said, they started having a professional army in the 1440’s.

The late medieval and early renaissance line is blurry in part because various practices got adopted at different times in different locations.

It truly is, as is the question when the medieval period started. Personally, I think it's fair to see the first "modern" principles from 1400 onwards. What is usually considered being classical feudal middle ages is, IMHO, earlier. That's why I think the 15th century is so damn interesting. It was the turning point after which European powers became the dominant powers. Up to then global domination was up for grabs.