I don't think it's media space restriction because Assassin/Hooks wouldn't be there.
Version 1 : 2nd Night : "Save Your Prayers" [SDB 62:19]
Version 2 : 2nd Night : Pre-FM (Z-Rock Radio) [FM 67:47]
Version 3 : 2nd Night : "Sledgehammer" Pre-FM [FM 73:51]
Version 4 : 2nd Night [SDB 65:01]
Version 5 : "War Machine" incl. Rhythm Of The Beast [SDB 70:57]
Version 6 : Vinyl Rip [SDB 59:34]
Well I don't know what "Pre-FM" stands for exactly. Looks like multiple parties had access to the soundboard.
I like No Prayer still I think the album isn't developed 100% and the sound isn't good...especially the combination of guitar sound and tightness live. For example, beneath Murray's Tailgunner solo there are some great staccato riffs. They are of Painkiller aggression without Painkiller production. And live is worse because Gers isn't being tight. Assassin is not a good track, and it's not a good live track, and they're not into it (the verses drag along more than on record). Hooks in You is also absolutely meh and did not deserve to be played live. Roger Glover would say this is a "sexy" song and Iron Maiden does not, I repeat, does not do sexy songs well.
I don't believe they chose not to play RSRD and Fates Warning. I still don't believe they didn't go for sleek modern production and push RSRD as single. I completely get, and approve, why Harris wanted a more aggressive route, I get why they booted Smith if he wasn't into it (I think that's why Stratton was shelved in the first place), but they kind of half arsed No Prayer anyway (Mother Russia being the obvious example of something in a beta version).
Technically if you could put on serious production, Mother Russia 2.0, replace Assassin/Hooks in you, you'd have a killer record.