Yeah, even if they're charged up with the blue spectrum energy (with whatever peculiarities of use it possesses) instead of the customary green, they're still Guardians. You know, the race with the strongest mental powers in the entire universe. I would expect that Ganthet and Sayd alone are more than a match for Larfleeze, and bet that the defensive aspects of the blue light will protect them better from the orange than green lantern power did the other Guardians when they confronted it.