How about this setup?

[JohnMc Senior Corps Member Find all posts View Profile Close JohnMc]

Guy as Warrior was tried, and it failed decisively.

Guy as Warrior may not have been your cup of tea but it didn't fail decisively. It was just another case of DC not knowing what they wanted to do.

[Trey Strain Guardian of the Universe Find all posts View Profile Close Trey Strain]

The numbers say otherwise. The last issue's sales were below 17K on ICV2, which means below 20K in actual numbers -- the cancellation point.

Trying it again and hoping for a better outcome is not an option.

Baz and Cruz are the ones who need to get out of the other Lanterns' way. Not Guy. And certainly not as Warrior again.

[Trey Strain Guardian of the Universe Find all posts View Profile Close Trey Strain]

This setup is reasonable and fair. It gives all the pre-Johns Earth Lanterns good camera time.

I'd call Hal's title Green Lantern: Coast City, and Guy's title Green Lantern: Space. But whatever. As long as there's no hint that one is an A title and one a B title.

Geoff can find non-Lantern roles for Baz and Cruz. As I said, a recurring mini would probably work best for them.

[Star-Lantern Weaponer of Qward Find all posts View Profile Close Star-Lantern]

From a practical standpoint, since Hal Jordan and John Stewart will be used in the supposed upcoming film, I would only focus on them as leading protagonists. Which... is actually what I would do anyway. I don't know what Lantern the films will use in the Justice League, but whichever is used (if any) is who I would have in the Justice League in the comics.

There are different ways you can go about this. You can put Hal Jordan on Earth and try to rebuild his supporting cast and rogues gallery, and John Stewart in space with the Green Lantern Corps. That seems the most basic thing to to, since Hal Jordan's fans seem to want to see him on Earth, and John Stewart really doesn't have a supporting cast or rogues gallery unto himself.

But...

Upon really considering it, I don't think Hal Jordan has a lot going on on Earth, either, which is likely why the writers don't often put him there. His rogues mostly suck, in my opinion. To be acceptable, they would either need to be reinvented or there would have to be new ones made. Either way, I think nearly as much effort would need to be spent establishing a worthwhile setting and villains for Hal Jordan as it would for John Stewart. Some of the villains are salvageable, like Doctor Polaris, but there are several others like Goldface that I just don't see any use for today. If I went that route, I'd probably reintroduce Jason Bloch as a villain, and reintroduce characters like Bruce Gordon, Rich Davis, and, of course, Tom, to the supporting cast.

John Stewart is nearly a blank slate if you decide to station him on Earth. The creative team would need to create a cast and setting, which is certainly doable (I'm not sure why some I've seen think it's impossible). Whether it would be great or not depends on the team involved, but I guess you could say that about anything. If it were me writing that scenario, I'd ride off of JL/U and involve the Shayera version of Hawkgirl in the cast. Or you can say Mosaic never happened and reboot Rose Hardin in some new role. Or do both. I'd, of course, keep Rose a single mother hillbilly, I'd just find some way to make that work minus the Mosaic World. It'd take some brainstorming.

For an interesting change of pace, I'd probably put John Stewart on Earth and build up a world for him there. We haven't seen anything like that with the character since the mid 1980s. I'd have Hal Jordan with the Corps in space.

As for the other Green Lantern characters, I'm not sure. If I was WB, it would depend on what plan I would have with them in other media, if any. If there wouldn't be any plan to use them, I wouldn't use them unless the story REALLY called for it. I wouldn't go out of my way to use them, though. I mentioned before that I don't have any problem with shelving characters if there isn't anything to say with them at the moment, or if where you're headed just doesn't need them. I would only focus on building up the characters that I'd plan on using in big films. The others are excess, in my opinion.

[Trey Strain Guardian of the Universe Find all posts View Profile Close Trey Strain]

The fact that Hal has no presence on Earth is just a failure of the writers and the editors. The setup is there, but they haven't used it. Hal would be the easiest to write in a solo title based on Earth. Just go back to the fundamentals there, with some tweaking.

To me the only close call is, where should John and Guy go? In the JLA or in space?

I think Guy would do well in either place. He'd present a good contrast to the other characters in JLA, and he'd do well in space with Arisia, Kilowog, Boodikka, etc.

I think the best spot for John is JLA, so give Guy the space beat.

[Trey Strain Guardian of the Universe Find all posts View Profile Close Trey Strain]

Let me hasten to add though that if the GL space title is about the emotional spectrum, it'll flop.

BTW, why has Hal's setup on Earth gone unused for so long? It's because the emotional spectrum has usurped its place in the comic's concept.