The ideal candidate for the modern Labour party would be a black Marxist transexual Muslim - apparently mostly female - and preferably disabled somehow: perhaps in a wheelchair. Such a candidate would tick all the boxes for them, but unfortunately, there is currently no such person available amongst Labour MPs.
So let's look at the likely runners.
Long-Bailey is Corybn in his younger days, with painted on eyebrows, lipstick, and a shouty voice. As I posted before in another thread, she will be the choice of most of the existing front bench and probably the unions too.
Starmer is a younger more articulate Corbyn with a knighthood. He's a man though, so has no chance.
Nandy, if she stands, seems the most human and normal of the bunch. Jess Phillips is similar but I don't know if she's considering standing.
That leaves Lady Nugee (Thornberry) - the most sneering and contemptuous MP I can think of at the moment (from any party). She's the one who had to be sacked when Milliband was the leader for making mocking media posts about an Englishman who was so racist that he actually displayed English flags on his house! And he drove a white van too! Disgusting! I'm sure that if she woman-splains loudly and often enough to leave supporters how they were misguided, stupid, or racist, then that will persuade them to give her their full support.
Tories will be delighted to have any of these candidates as the new Labour leader as it will likely gift them another fifteen years in power. Nandy or Phillips would worry them the most - but I've yet to see a candidate that will really trouble them. The rot for Labour began when they elected the wrong Milliband as leader, and locked themselves into a system where their activist mostly Marxist members get to choose the leader - and the MPs have relatively little say in the matter.