Howdy!

So I went a little overboard on cables and got Thunderbolt 4/USB4. USB3 10Gbps would be ample for these devices, I'm just silly like that.

Of your devices, the two capture cards (HD60X and CamLink 4k) are the two that need bandwidth and their own ports. Technically, if you had Thunderbolt 3/4 hub there is enough bandwidth, but those are like $400 and hard to find in stock. The Stream Deck and Snowball should be fine behind a USB3 hub as long as it is externally powered. Notice my USB3 hub is quite large, but externally powered so all devices get what they need. With your MacBook Pro you have 3 USBC ports, so one each for the video capture cards, and you'll need a good hub for the Stream Deck and Snowball. You might be able to get away with an unpowered hub with just those two devices. On the MacMini, you can plug your two capture cards into the USBC ports and the Stream Deck and Snowball into the USBA ports, if you don't have additional peripherals.