The explanation of SN 35.23 Sabba Sutta in ṢaḷāyatanaVagga

0. History base knowledge about wrong and right view: See SarathW's Answer.
Then:

1. Why are these called "The All": the eye & forms, ear & sounds, nose & aromas, tongue & flavors, body & tactile sensations, intellect & ideas?
2. Why someone trying to explain "The All" as being something else would fail?
3. What does "it lies beyond range" mean?

The wrong view has the wrong condition(s). The right view has the right condition(s). The all right condition is the dependent origination, because the conditioner and the conditioned relate each other in balance, nothing left out of the cycle of the condition.
the dependent origination explains "Thus arises this whole mass of dukkha".
Each conditioner of the dependent origination causes the whole conditioned effect. For the example, ... the (Six-)Saḷāyatanas-conditioner causes the whole conditioned Six-Phassa; The Six-Phassa-conditioner cause the conditioned six-vedanā ...
So, if one, who questioned, explains the All, whole, into the dependent origination as the Buddha did, that one is able to explain the whole from the beginning to the end follow to the dependent origination such as the Buddha can explain every view in Sutta. Tī. Sī Brahmajālasuttaṃ.
But if one, who questioned, explains the All, whole, out of the dependent origination, that one would be unable to explain, and furthermore, would feel hard to answer (fail). Why? Because it is beyond that one's abilities, he exactly answers the wrong condition (fail), i.e. God condition the being.
SN KhandhaVagga and SN ṢaḷāyatanaVagga, such as SabbaSutta, come after SN Nidānavagga, the dependent origination because they are the whole elements which cycling in the dependent origination.