Dear Esteemed Bicephalus President of the Galaxy His Honourable Zaphod Beeblebrox,
I think the “zero common ground” argument is a little like this. There have been several decades of Chabad Rabbis developing a philosophy and movement that the rest of the frum world is extremely opposed to. Chabadskers who follow those Rabbis by definition will ignore any Torah or Hashkafa from the rest of the frum world that doesn’t suit them.
So there’s no common ground, as any argument will be “The Rabbonim say that this is how to interpret the Gemara” with the response being “But my Rabbonim disagree”. It’s the same with Conservative and Open Orthodoxy. If you choose to follow a Rabbi that plays loosey goosey with the words of Chazal and ignores everyone telling him “No”, you can’t even begin a debate.