Maybe I am deluded, but from the first debate onwards I thought that Bernie and Warren were working as an informal team. There are real differences between them but they pale between the divergence between them and the other Democratic candidates, and I think both recognize this. I suspect that Sanders is more ill than he is letting on, and I think both are patriotic enough to put their differences aside if the other gets the nomination. Then again, I am less sanguine than you about the contest. Big money baby-boomer neoliberal Dems want Biden or an acceptable Biden substitute (I can fairly hear Andrew Cuomo champing at the bit if Biden goes down in flames…BTW I am on record on Medium as an age-cohort traitor to Boomerland. I generally disdain “M-m-m-m-my Generation”.)
Another thing is: the depiction of Warren and Sanders are “far-left” by both establishment Democrats and Republicans in general would be laughable were it not so dangerously pathetic. Both are mild Social Democrats. We need far more drastic economic, political, and social change than either of them advocate. But politics is the realm of the possible, and you work with what you have.
Finally, I lean toward Warren largely because she has specifically targeted Big Tech, and Social Media in particular. As a tech-person I am on to both its benefits and dangers. Amazon and Google need to be broken up and/or their sell-our-users-as-a-product business plan made illegal. Facebook and Twitter need to die. Period. At this time I use them only to promote my writing. They are an existential threat to intelligent political discourse if not intelligence as such. A public utility for instant messaging and posting or promoting one’s work should be set up. You’d see a significant exodus from Facebook and Twitter. As Zuckerberg well deserves.