What do you want a single to do?
You have to answer that question before you can hope to guess which the 3rd single will be.
Probably reasonable to think that the label (and to a lesser extent U2) want it to help sell the album. The label obviously would like to make cash but for U2, and their ambition to remain relevant, I'm sure it's important that the album do well in sales.
That said, we are probably past the crucial selling points.
Magnificent is the classic U2 song but since it was preceded by the oh-so 21st century U2-sounding Boots, I think Magnificent probably went down on a lot of deaf ears.
And let's face it, everyone knows U2, they don't need the exposure of the album, they need to expose that the album isn't as conventional as they've been. So would U2 want to throw something a little different out there to try and catch on some new listeners? Given that the the idea to 'sell' the thing with a catchy song is probably not a great one?
Well like others, I think there's only one of three ways to go here.
Choose Crazy Tonight and try and move units with a pop single.
Choose something a little off the beaten path, like MOS or UC.
Choose Breathe for a comfortable rock choice.
I think MOS and UC have little chance of being performed live, so I rule them out as the 3rd single (maybe 4th or 5th).
So I would think they'd go with Crazy Tonight or Breathe next. Probably the former.
If it were my decision I would choose NLOTH, although it wouldn't interest many poppy heads, it's also not a standard rocker that's going to get a lukewarm reaction from those skeptical or ignorant to U2 but not ignorant to bluesy rock from the last 40 years.
So yeah, I'd go with NLOTH. Fuck it, why not?
There are some great choices here but the idea has got to be to open some eyes and tune in some ears. Try something a little different.
I dunno, if they released Unknown Caller or MOS, I would be the first to path them on the back, I just don't think they will get a version live that they are happy with. UC will not work without the big greek chorus.