They are effective, but more so during certain times of the year.Fighting sounds fox and raccoon definitely work. Coyote fighting sounds I have not tried.
I agree...fawn bleats get me nowhere in the middle of winter.I have noticed that most types of calls used have better times to be used some in the fall and late summer , some in the winter , some in the spring and early summer and some in full on summer . I have found that for myself that when I figured out what worked best at one time of the year it did the same year after year for me .