If in doubt MCPA at label rate for the species if grass.
We're using an interesting new one called Pylex on our Bent grass greens at the moment. It specifically targets broadleaf species and warm season grasses like Ky and Couch without so much as touching the cool season Bent. Results have been remarkable, we didn't realize just how much the other species had invaded our greens until they started dying off. In fact they look pretty average at the moment but the bent is pushing through the gaps and they should be pure in a couple of months.
Not cheap at around $1000 and application, 1ha/2 for which we need two apps.
https://nuturf.com.au/products/plant...ylex-herbicide