tend to agree with this. if each board is drawing <400W you could provide that with only 2 cables. my guess is that it does two things:
1) prevents people from burning up cheap 18awg cables (that are limited around 150W)
2) slightly better balance of power distribution so the connector or copper traces dont fail
I absolutely understand that the official line will always be use all 3, however the technical explanation as to why you must use all 3 didn't really make sense.
Maybe someone who has an S5+ can tone out each side of the power connector pins. I think it's that simple, right?
If they're all connected with no resistance, then they're all going to the same place.
That would mean the pragmatic answer is you can probably use 2 16 AWG cables.