The thing is, right, the thing with this is, you seem to be basing this all on the idea that, for instance, Northern Ireland was a conflict between nationalists and unionists, and the Falklands was a conflict between the islanders and the Argentinean state, with the British state as a neutral third party in both instances. But I reckon most people would probably identify the UK as being an active participant in both those conflicts. And I reckon Corbyn has a decent amount of knowledge of the British state, and has met with British politicians on multiple occasions, and some would even say that being an MP makes you a representative of the British state in its own right, so once you take that into account the idea that he's only met with one side of the conflict starts to look a bit wobbly. And even treating unionists as being totally independent from the UK, which is questionable, it is still the case that Corbyn has spent a fair amount of time in Parliament, which usually has a few representatives from parties such as the DUP and UUP, so it's not like he's so totally cut off from them as all that.
I mean, in this metaphor Corbyn's a screaming toddler, and maybe that's fair, maybe that is what he's like. But the problem with this is, that screaming toddler still managed to give the right answer on one of the major geopolitical questions of the 2000s, whereas the sensible Blairite mainstream got it so murderously, disasterously wrong that a decade or so later, a lot of people were still willing to go "well, maybe I don't agree with that screaming toddler (who I guess is an adolescent now? I dunno, not my metaphor) about everything, but at least he was right about Iraq, and he's not directly responsible for the rise of ISIS." So that still doesn't look great for the sensible Labour mainstream, if their judgement is disastrously, catastrophically worse than that of a toddler having a tantrum.