Red, Green, Yellow, etc..
Have similar power sets. Do you think this is unimaginative? Should they have differing power sets? Should the Green Lantern Corps members have different powers?
No, I don't think it's unimaginative. First because calling this judgement would mean I'd be able to come with something better. I'm not. Second, because they're all lanterns.
I think the mistake is to think the lanterns are the only bad guys in the GL mythos. Look at Evil Star -> not the same powers. Look at King Shark -> not the same kind of powers, look at Black Hand -> not the same kind of powers, Cyborg-Superman, Mongul, the manhunters, the first lantern (he's a lantern!), the Weaponers of Qward, ...
I mean, recently the Lanterns became the main bad guys for everything, but the others vilains should not be forgotten, they display a whole different kind of threat or powers.
Beyond that, I don't think it's unimaginativ, on the contrary, the power ring is able to create constructs, that's the deal. If someone want to have another power set, let's use someone else rather than a Lantern.
It's a bit like saying Jedi are unimaginative because they all use light sabers. Yes, it's how they do.
Personally, I'm fine with having giant colorful constructs all over the sky in a type of space opera adventure.
Bottom line : Larfleeze have a peculiar way to se his ring. The Indigo too. The red lanterns can't make construct except Atrocitus. The Star Sapphire make crystals to trap their ennemies.
I think your thinking may be about the Sinestro corps (or so I suppose). And you'd be right about this one, they are doing stuff similar to the GLC. But again : Since his creation, Sinestro has use a yellow ring to
replicate the power of the green one. So it's seems logical to me.