IMO call sequence has to change with the current situation - time of season, habitat, etc for the best results. And using distress calls alone means a lot of missed opportunities, whether mouth calls or electronic doodads.
Coyote vocalizations to fit the situation always start my calling sequence no matter what time of the year or habitat, and are often enough alone with no distress call used at all. The distress calls are saved until after I get a response or don't to the vocalizations, along with them if I get a response, for keeping them coming or to stop them for a shot. While I agree that matching the local prey is a good start for distress calls, mixing it up by throwing something at them they probably have never heard before can often make the difference between getting a shot and not in hard hunted areas where they have already learned to recognize store bought distress calls. While I made all my own mouth vocalization and distress calls for around 5 decades, I also used a lot of oddball things to get their attention and get them coming when nothing else was working. Things like toy Halloween clickers, kazoo's, slide whistles, animal/bird diaphragm cans, etc. Predators are very curious and will eat almost anything, so don't be afraid to try "anything" within reason. And don't over call, ever. Put it out there and then clam up for a few minutes. If they are coming, let them and don't toot another hoot unless they hang up. And when you do keep the volume down to further spark their curiosity. I use lip squeaks (I've brought seen coyotes on the sneak to a stand all the way in with nothing but lip squeaks when the wind was not too heavy).
FWIW