I will add an additional POD to make things easier, Peter Shore wins the 1980 leadership contest (Foot stands aside as originally intend and Healey loses because Denis Healey). Quite a few eventual SDP members stated that Shore would have likely lead them to stay due to his more aggressive action against the Hard Left (But also having Soft Left credibility and all that) and likely would have seen Owen stay around (I remember reading that Shore had an okay relationship with Owen though they did have there differences, but Shore would probably hand him a decent portfolio or something).
Just adding that there because it’s likely to be the only result that doesn’t have a proper SDP split as it were, probably a TIG like Group maybe lead by George Brown would form but nothing major, without the early momentum of the SDP behind it, any other Centrist split would likely be dead in the water.
But that’s adding more PODs to it already.
There probably would be a moderate split but less severe as it were.
In terms of Roy joining the Liberals, I could easily see that. His socio-economic, political and geo-political views were easily aligned with Steel's Liberals.
I think it’s been mentioned multiple times that if the SDP hadn’t happened when it did, Roy would have wandered off with a few friends to join the Liberals/start his own Centrist party which likely merges with the Liberals.
I thought I would mention that on the outset, because Roy Jenkins isn’t likely to shake up internal Liberal politics too much, I doubt he would be leader and all that.
But Williams was fed up. Rodgers was trying to find a reason to hang on, but was exhausted with the nonsense.
It’s fairly easy to have Williams and Rodgers bugger off to the private sector as I believe it was an option considered before they got the support of the other two.
Where all of this would have ended is a good rabbit hole down to which lose yourself. But when I did my SDP timeline (thumbs up, cheap pop/plug), I found the biggest obstacle to a timeline where SDP or the Liberals do "better" than in OTL is not alignment, so much as Falklands. With Falklands going as it did in OTL, short of Labour imploding even worse (which is what a @SeptimiusSeverus's
Breaking the Mound TL does), it is very hard to see Liberals or SDP doing much better than OTL and it all going as it did.
I have read your timeline a bit, and I think it’s excellent (though I find you’re characterisation of Bryan Gould slightly off, not by much but still).
I set up this thread mainly as a reaction to the multiple SDP timelines, there’s a number of them and not many ones discussing the Liberal party in a No-SDP world and how it would have handled the 80s without the Alliance. Steel would probably eventually step down in the Mid 80s, mainly because I doubt there would be a Liberal explosion in the 80s, given everything that happened in OTL.
But beyond that, not much of a clue. Penhaligon probably would become leader given the relatively slim pickings for 80s Liberal leaders (apart from Alan Beith who would probably just have the Liberals do, just fine etc).