I just assumed the placement and positioning of turbines within a cluster was already subject to rigorous modelling, seeing as these turbines are huge and likely very expensive
For example: https://www.siemensgamesa.com/en-int/newsroom/2019/11/191126...
What's novel here is the effect the counter-clockwise rotation has on the power output of the down stream turbines... I think it hasn't really been a point to research as the costs of blades, maintenance, etc... are assumed to far outweigh the potential gains.
Something else to keep in mind is that it's not as pleasant to look at a park full of turbines spinning in different directions.
Stands to reason that the same thing would be the case with wind turbines, and maybe a little surprising that it hasn't been on anyone's radar before now.