Yeah, "Squonk" would be a crappy name. But Genesis rarely had title tracks at all. "The Lamb" is a bit obvious because it's a concept album; "Duke" is the same, almost. But other than that, there's "Invisible Touch" and "A Trick of the Tail". The rest are unrelated, save for a few inspired by lines from songs, but not the song titles themselves. My guess is that "A Trick of the Tail" had some kind of hidden meaning. They had just lost their lead singer and front man, and most everyone expected the band to either break up or fail completely. Instead, the drummer took over lead vocals and they just carried on, seemingly without missing a beat. It was a "trick" they pulled off quite well.
"One for the Vine" is easily one of my favorite Genesis tunes. I love the "Follow me" section. First time I heard the song, I kept waiting for it to come back; it seemed like the "chorus" after those long verses. Nope. It was, as Tony Banks put it, a "throwaway" part.
I read an interview with Tony back in 78, just after "And Then There Were Three" came out, and he spoke of how their approach to songwriting was changing, how they used to intentionally juxtapose quiet sections with louder sections for effect, and often include throwaway parts in songs. This didn't mean that that section was in any way inferior; it just served as the musical backdrop for part of the story, and thus didn't come round again.