Team enough for CLS?

They ought to be.

but you really need to get luke farmboy to level 85... thats like a minor upgrade that just has to happen...
plus i'd advise to get old ben gear level a bit higher... he is a really valueable tank
don't forget to Mod them up too and good luck !

personally i made it my priority to get this squad all at gear level 11 (last purple one before it turns gold)
that's after i got my a** kicked at the thrawn event - the difference between phase 6 and 7 was crazy... so i'm not taking any chances here.

You do not need to take Old Ben past G9.

G11 on all your toons is overkill. I haven't done the 7* Thrawn event but that is supposed to be much, much harder.

https://swgoh.gg/u/tvf/collection/?f=rebel

I haven't touched anyone other than R2 since the CLS event. Three G9's and a G8.

Press that green auto button :)
I think talking strictly and only for the CLS event, you don't need any more investments at all. You might not even need any mods, not to mention any decent mods.
But you need to get 7* R2 before CLS returns