They have nobody lined up. Henry of Richmond was their last credible claimant. I can't see them being so dense as to risk their lives in England twiddling their thumbs over finding somebody they already know doesn't exist. They need to attach themselves to somebody already running around, and it sure as heck isn't the Ricardians.
I agree there's no obvious contender -- I said just that in my first post in this thread 🙃 That doesn't change the fact that both the Lancastrians and the Edwardians need each other, though, and that a marriage between a Lancastrian (probably Jasper) and Elizabeth of York is the cleanest way to unite the two factions.
I've already explained that the Stanleys will switch sides to anyone who benefits them; they aren't Lancastrian loyalists. And the Lancastrian army at Bosworth was also inflated with French mercenaries whose interests aren't going to be aligned with the Lancastrian cause very strongly either.
Except the Stanleys have no place to go now. Their intervention at Bosworth changes their position in the kingdom rather dramatically -- they simply cannot reconcile themselves with the Ricardians after the being the deciding factor in the battle that killed Richard himself.
I think you're vastly overestimating the capability of the Lancastrian holdouts here. There weren't that many of them in exile to begin with, they have no claimant (even Henry of Richmond was the bottom of the barrel), and many of them have already got what they've asked for. Whether they go with Warwick or the Elizabeth of York/Elizabeth Wydeville circle, I'm not sure, but I can't see them going with Lincoln given they've pretty much alienated themselves from the Ricardian cause by helping take down Richard.
And there just isn't anyone else for them to rally behind. Buckingham? He's too young to marry Elizabeth and his claim makes Henry of Richmond's look positively sterling by comparison.
And I think you're overestimating the capability of the Edwardians 🤷♂️
There were reportedly 400 exiles in Brittany, which is a small enough number on its own but would be entirely drawn from the nobility. That is a pretty sizable number of lords, knights and squires. There were 6500ish Lancastrians at Boworth, of which 2000 were Frenchmen. That's 4500 men drawn primary from Jasper's Welsh allies and the Talbot men. I doubt the Edwardians could raise much more than this. Yet, if we look at Stoke just a couple of years later, we see that Lincoln is able to raise about 8,000 men. The Edwardians and Lancastrians need one another to survive.
Honestly, Jasper and Oxford playing Kingmaker and installing a Yorkist King of their choice (Warwick) is the most logical decision they could make imo.
How on earth is choosing a child with no support whatsoever the most logical decision? The figure in question is such a political nonentity that 1) Richard III just ignored him entirely during the usurpation of 1483 and there is no record of anyone objecting to this, 2) Richard murdered the princes in the Tower and there is no record of anyone floating Warwick as a possible contender to the throne, 3) the Ricardians would promote the imposter Lambert Simnel before rather than take up Warwick's cause, and 4) Edwardians alienated by Henry VII's reign would promote the imposter Perkin Warbeck rather than take up Warwick's cause.
The only people who ever seem to have been interested in Warwick are history nerds like us who think "Well, there
was a male line Plantagenet running around" -- but there's genuinely no evidence that anyone at the time cared.
