SO... if you're looking for an answer.... this might not be the answer but it should get you pointed in the right direction.
There's nothing magical in that mix. It's simply good engineering and excellent recording.
Start with good singer. Layer the tracks.... record several lead vocals... record the harmony parts and be sure to get several tracks there as well.
Be sure the vocals are "phrase perfect". In other words, all words have to start and stop together, nothing needs to be out of sync. Use the lead vocal as your guide. You can either punch in to fix the mistakes or use something like Melodyne. Once everything is phrase perfect, next step is to get them pitch perfect for the part. Do NOT clone. Record everything new. This stage of the process is where you will likely spend the most time. It has to be perfect right down to the inflection imparted to the way you pronounce or accent a word. You are working in a world of DETAILS. So pay attention to the little stuff.
As far as mixing it.... this is a starting point guideline to get you rolling. Your individual needs may vary over a wide range from this.
Put the lead up the center..... balance the other leads equally opposite and really low. You don't want to be able to hear them necessarily unless the vocals are soloed. All they are doing is adding a subtle fullness to the vocal track. Do the same thing with the harmony parts... But the harmony needs to be up a bit so it is slightly audible to add that harmony feel to the vocal. And THAT is for ONE VOICE. Each different voice in the project will require the same general treatment. With 2 singers, you will likely have 10 to 12 tracks or more just for the 2
vocals.....assuming you get a good "one shot take" on each part.
EQ, compression and reverb.... these are added to taste. A little compression to even things out, the EQ to bring out the sparkle, and reverb for the feel you're going for. On the Floyd song, nothing sounded excessive there. Perhaps a bit heavy on the verb but that's par for the course with PF.
It might take you several tries to get this right.... because it's something that takes time to do it right. You can always zero everything and redo it if it doesn't sound good the first or second time.
Lots of pop stars and even country... or should I say, especially country stars use this techniques in just about all of their songs. I've heard that some engineers record up to one hundred vocal lead takes and piece the track you hear on the radio, together, from those tracks.... I'm good with 5 tracks for the vocals.