It depends on how you plan to 'trim' them. I'm actually against killing any of them. Last thing the GL fanbase needs is more outrage as one group's favorite Lantern is killed. I think at this time, about the only one you could 'safely' kill would be Baz, and then you'd probably get some media and social media backlash about DC killing one of its only muslim heroes.
Now, Guy made a pretty good red, and if he'd stayed that way I'd be fine with it. Or, god help us, let him get that blue ring they kept hinting at in future peaks and let a good writer have fun with Guy inspiring hope and pissing people off at the same time (It would be like a coach from almost every hollywood football movie ever )
Hal and John's fan groups are very passionate, and I would be very cautious about retiring either of them. Let them be the two GLs of this sector.
Kyle could go back to being the White Lantern. Not everyone likes that, but it would be helluva lot better than killing him off. Frankly, I'd almost suggest letting him have a happy ever after as he quits the ring slinging due to literal emotional exhaustion, goes home, finds a nice girl, gets his art career kicking, and voila bliss! But we all know it would be two years tops until someone at DC decided to put him through #### again or even kill him.
For Simon Baz...seriously, I've no idea. A writer might be able to kill him and if DC could endure the internet backlash, the actual fan base might be tolerant of it, but it sure wouldn't set the best precedent. Maybe a better idea would be to have his ring start to malfuction due to the unnatural way it came about...and fade. No new ring comes to replace it. Then you can decide if Simon just fades into comic limbo quietly or gets a new source of powers and becomes another hero entirely.
But that's just my thoughts on it.