Scotland is a countRy, not a county. Thus, though Yorkshire has a population roughly equivalent to Scotland's, there is no prospect that the former will ever be allowed to hold a referendum on independence from the rest of England! It has nothing to do with numbers.
Many Scots turned away from Labour when they saw Miliband "on the same platform", in effect, as Cameron and Clegg during their referendum. All three signed up to a vow - not just a vague 'promise' - to give Scots greater powers within the UK.
Of course, the very next day, Cameron said these powers would be 'tied' to progressing alongside EVEL' (English Votes for English Laws), even though there is no real connection between these processes. So that rather blotted his copybook in the eyes of many north of the border.
As you yourself say, Mikey, re Gordon Brown, "It's widely recognised that his intervention made a big difference in the closing days of the referendum campaign." That won't have helped Scottish Labour's position either, will it, if they began to feel it was all a bit of a con? Having and eating cake is not the same as believing your cake may just have been snatched from your hand!