Not a bad idea, but you really need 2 regular series for this to work.
A lot depends on how easy it is to travel between the base of operations of the two teams. If it's nearly instantaneous it almost doesn't make any difference from having a single team, from a narrative standpoint.
If it takes a while, it creates some interesting dynamics... some Legionnaires could push to be put in the same team of their romantic interest; it'd be easy to create a contrast between "what's best for us" and "what's best for the Legion".
I could see assigning Brainiac 5 the task of making a list of who would be the most efficient in which group, and then let someone like Saturn Girl make the necessary adjustments taking into account each personality and not just the powers (you know Brainy would mess that up).
21) Superboy
22) Supergirl
Having those two in the same team kind of defeats the purpose of splitting the team, doesn't it? I think it's better to separate them, otherwise Supergirl inevitably ends up playing second fiddle to Superboy.
I would have her and Andromeda switch places.
Some, like Tyroc, don't really work with a deep space team (no sound in space...)
It's been ages since I've read Tyroc, but was it really a limitation that we've been shown? I know that logically his powers SHOULDN'T work in space, but then we have Superboy using super-breath in space.....