This is one of the biggest changes my LS made that helped us clear Ceizak early on, we replaced a Geo with it. Another is to use an Embrava during Mastop. All of the rest of the advice is good stuff/important as well.
Not that your setup can't work, but we personally go with 2x Mnk, Drk, Drg, 2x Rng for the DDs. We've had Blus come and it's not that they're not useful, just that they're typically our support jobs. We had tried more Rngs in the past, 3-4 of them, and it seemed to create issues on other NMs more often than not.