I'd say only Karl Urban was famous enough that most people would have recognized him somewhere on earth prior to this show, but of course Chace Crawford hit the jackpot when both Gossip Girl but especially The Boys became viral hits. Some weeks both shows top the streaming charts worldwide which says volumes about their long-term success and reach worldwide...
Antony lived in Oslo, Norway for 2 years in his early 20s when he got hooked on snowboarding and wanted to be close to the action. He used to work for my brother and was part of the Sunday football gang (the real type of football) and he was a pretty decent attacking player with skill and speed so always ended up scoring the goals. His Norwegian used to be quite good back then.
2:03 the episode being shown is where Jack Quaid's character meets Alice Cooper and gets put in Alice's infamous guillotine. It's how Hughie got the balls to stand up to Homelander
What about Ashley, Also Ashley, the two writers (I mainly know the one guy from the Sunny episode "The Gang Gets Racist"), the director guy, Victoria Neuman, there's so many more than who you mentioned.