I can't say I have followed all the ins and outs of May's Brexit debacle, but it seems like May's problem, and for that matter the problem of most of the Tory party, is a continuous refusal to acknowledge that the EU, not the UK, holds most of the cards. The British are inherently in the weaker position, but the Tories just can't seem to get it through their heads that they have no power to force the EU members to give them better terms. I guess it's a kind of British Exceptionalism. It is like they expect the rest of Europe is going to decide that the Britain is inherently superior and deserves to have a sweetheart deal as it tries to piss all over the EU project.
Brexit is going to be a disaster as long as they won't drop that Delusion. But they can't drop that delusion because that is the delusion that drives the Brexit campaign.