I would also look at a munters heat recovery wheel, they can handle both latent and sensible parts of the cycle.
I have seen them used in a similar application where there was a large % of OA air and a requirement for latent cooling (de-hum) and not much sensible cooling. It was in a bar /...
This to me looks like a retrofit (maybe design) because the latent cooling in the existing coil was insufficient for humidity control.
By doing it this way the latent cooling / dehumidification is controlled rather than before the coil where the 'cooling coil' will also have a dehumidification...
