Ok, mating season for coyotes is now, started about late feb and can run into april
so seeing several together can just be a bunch of males on an in heat female
with this info, female dog calls can help a ton
second tip
go to some animal shelters, ask if they have any females in heat
if so, ask if you can get some urine
and use it like doe in heat
know many folks that have great luck with doing this

next, how long are you setting up both before calling, and after starting to call
I am one that has had better luck with waiting 30 40 minutes nefore calling, after getting to calling site, than just setting up and calling
coyotes are super smart
most guys maybe get one for every 25 30 sets
so, hang in there
also, coyotes are more active at last 30 minutes of light than mornings too