I actually think all of the anime G4 got was actually stuff licensed by ADV films, who I believe also ran the Anime Network (Like the actual channel you could have payperview). That's why a lot of their shows were stuff that you wouldn't see on Cartoon Network since VIZ usually got the rights for those ones. The fact they aired Cromartie High School though is fucking legendary, that is imo in the top 3 dubs of any anime for actually being better then the original Japanese version.
My guess is probably related to problems G4 already had. The Decline of G4 video (Posted in this thread) goes more into it but G4 was really only broadcasted to networks that included in it's lineup and even then you had to actively search for it. I dunno how it is for others, but over here in the North East I had Comcast, and G4 was specifically channel 219. There is no way in fuck you would find that channel without searching or surfing, and even then you had to pray it was playing something relevant to even know what the channel was about if you were surfing. Back during it's hayday (Before TechTV merger) I only found out that the channel was about video games because Cinematech was playing a demo for the Bruce Lee game on Xbox. Otherwise I'd assume it was just another channel.
You add in Anime already being niche as it was (The Inuyasha airing times for adult swim is a perfect examplesof it), and put it on a network not many people may know about it and it's just going to cause problems. That's why they later on went to get syndicated shows like Cops and went fucking ham on Ninja Warrior since that's something more general people would enjoy and would bring consecutive ratings no matter when it was airing, albeit being a slap in the face to fans of the network.
Actually every single anime TechTV/G4 aired was licensed by Pioneer/Geneon until 2005 when they aired a slew of ADV stuff (starting with Magical Shopping Arcade Abenobashi, which I forgot to mention was one of my favorites that they aired) which would be the final run of anime on the network.
Around 2005/2006 ADV made a big push to get their stuff on TV in general beyond their own Anime Network, there was the Adult Swim airing of Evangelion in 2005, which off the top of my head is the only ADV series I'm aware of that aired on Adult Swim and I believe it's also noteworthy because it aired only one time.
There was also Chrono Crusade airing on Showtime Beyond, which is weird because I think that was the only time an anime ever aired on a Showtime network.
As for Pioneer/Geneon, their stuff aired on mostly TechTV/G4 and Starz network movie channels like Encore Action, I can only think of two that got Adult Swim airings off the top of my head, Samurai Champloo and Paranoia Agent in 2005, although Tenchi Muyo aired on Toonami and that was also Pioneer/Geneon.
The vast majority of what aired on Adult Swim was Funimation and Bandai USA licensed stuff.
Then there was a smattering of other random, smaller publishers, Manga Entertainment had the Read or Die OVA air on Adult Swim and I think they were the publisher of Ghost in The Shell: Stand Alone Complex as well, although that may weirdly have been a coproduction of both Bandai and Manga, I'm not sure.
But most Manga stuff aired on Starz networks like Encore Action.
Then we get into the more ones obscure like Media Blasters, that had the series Gokusen air on one of the Starz Encore networks and Central Park Media, which I think only had TV airings on the Sci Fi Channel, speaking of which Sci Fi Channel had another attempt at an anime block circa 2007 that aired series from various publishers although I'm not sure which ones, that's about the limit of my knowledge of anime airings on US TV.
Although there's also a
really obscure publisher called Synch Point that originally licensed FLCL which of course aired on Adult Swim, I think Synch Point might have only released a few series overall.
