I often read the admonition that splits should only be made from overwintered hives, but I'm curious about why. Is it just so that the queen is a proven performer? If, say, your most populous hive was a swarm installed just this season, why would you not want to mine a few frames from it?
I ask from you, why you want to split just fouded hive?
Swarm? - What swarm? 1 kilo or 5 kilos?
Swarm, is actually wintered hive bees. It just escaped.
When you have 5 box hive, you may split it ito 50 mating nucs. Queens mate and you have 50 mated queens. To make them hives, you need 250 frames bees to make them minimum hives.
What then? You get them alive over winter. They build up 6 months and then you have 50 5-box hives.
You did not get much honey but you must bye 2500 frames and wax sheets and 200 boxes.
Then you need a 200 square meter big store house, where you keep all beekeeping stuff, your new car and ......