I love the horns in Heroes are Hard to Find! It was an unusual, untypical addition, but it suited the song. Are horns not acceptable in rock and roll? Tell that that to Bruce Springsteen, tell that to Chicago, and numerous other bands that I can't name at this moment.
Christine's body of work in Fleetwood Mac circa 1971-1974 is exceptional; her contributions added a level of appeal and dimension to the albums. I just love those albums. But when I became obsessed with the band in 1977, their back catalog was a complete mystery to me.
Much like many other listeners who fell in love with their self titled "white" album and Rumours, they went out and bought those previous albums, not familiar with the band's back story, and unaware they weren't going to get the same band or sound. My older sister had bought Future Games and Mystery to Me. I inherited the albums and was completely fascinated by them, having very little knowledge of the band's history, or the context in which the albums were made. Over time, I enjoyed discovering their other albums -- Kiln House, Bare Trees, Penguin, and Heroes are Hard to Find, and learning the complex evolution of the band. Only later did I get into their blues era material.
By the time Stevie and Lindsey both released their first solo albums, I was in deep. Hard to believe the band has been the primary soundtrack of my life for 37 years!