In my experience it's super annoying to fix with it in the beginning, but the easiest thing is to just get a no bullshit desk mounted one with 3 mounts on the same bar, and then not have to deal with with separate arms; which is awful to no end. And then just tape them together in the seems when they are lined up. Works wonders.

Most wallmounted monitor arms are on one single bar, meaning they essentially work the same and have the same issues. But you won't have to deal with the height adjustable desk problems :)