WWL 870 is a two tower directional with a broad cardioid pattern, daytime and nighttime. It is a bit more than 50 KW ERP towards New Orleans.
There is seemingly the idea that stations would not want to be directional if it were not a condition of licensing. As you point out, WWL benefits by not "swimming with the fishes" in the Gulf, just as WBZ directionalizes to cover the populated areas around Boston better.
When in Ecuador, I got the opportunity to put on two stations, one each in the two largest cities. I decided to go for 10 kw on each, even though the two locations are only about 200 miles apart, edge of the metro to edge of the metro. I installed two directional systems. For Quito, located in the Andean highland zone that is almost pure north to south with little population to either side, I did a two-tower directional using equal length coax (measured electrically) from the final stage of the transmitter to each tower. The spacing did an elongate figure 8 without sharp center nulls. It had nice coverage for over 100 miles to the North and South.
In Guayaquil, on the Coast, we located in salt flats SE of the city and shot NNW by SSW over the coastal population areas.
Neither had phasers. Just electrically identical coax feeding each tower. The towers were spaced to achieve the desired pattern, which, since not imposed by regulation, was at our discretion. All done with a Cleveland Institute electronics slide rule and a Potomac OIB.
Buy directionalizing, we were able to use the frequency in the two biggest population centers without cannibalizing the coverage in between the two by interference of two 10 kw non-directionals right only a few hundred miles apart.