Nightlife and Little Darling...Nelson, Marvin, Lynott?!

I've discovered that Marvin Gaye did a cover of this Willie Nelson-penned track in 1966 - as did Doris Day in 1960 and B.B. King some years later - so that begs the question: who/what was Phil Lynott thinking about by referencing this song? Marvin Gaye, perhaps? Those strings on the arrangement sound a bit like a Gaye track...or maybe Phil was thinking about B.B. King, the quintessential blues guitarist, and his version. What's also fascinating is that the same 1966 Gaye album has a second track relevant to Lynott's oeuvre: Little Darling (I Need You) shares a title with the 1974 single 'Little Darling' by Thin Lizzy. I find that interesting, because I know Lynott was an R&B fan (and exponent). Behind the swaggering vocals and (proto-punk?) screaming guitars of his LD single, I hear that there's traces of Motown in the Lynott song, with those descending horns in the background...! And then the Doobie Brothers did a cover of it later as well....in such ways are musical connections made. So what was Phil up to? Worth a closer look.