The movement is 8-bit, which tends to be jumpy. If you want smoother movement, you need to upgrade to a fixture that has better stepper motors and most likely also has 16-bit movement control(X+Xfine and Y+Yfine channels, 4 channels total in the case of a moving yoke fixture). It's not a controller issue, you'd have the same problem with any controller surface or software, because it's a motor and control issue. You could adjust your fade times to try and get a bit of the jumpiness out of the picture, but it won't really address the problem.
If you point them both to the same location and one is higher than the other, then one of them is aimed higher on your stand or truss, which is a super easy to make mistake, which of course is happening by accident anyways.
If you get a fixture with better stepper motors, even if you don't use 16-bit movement addressing, you'll at least be able to get the smoother movement you want. I'm using some Chauvet Q-Spot 150's(moving yoke heads) and despite issues I have with the fixtures, movement has always been smooth. They only jump when I want them to jump. My main problem is that there is too much movement between values on X or Y, which is why this fixture has X and Y fine movement channels. Of course, it's no secret that I'm looking to replace these with some sort of equivalent fixture from ADJ soon, perhaps a VIZI series fixture.....
Also, thanks for respecting the "not a marketplace" rules. You did well. You're not listing prices and are requesting people to contact you directly. This is an excellent example to all for how to do things properly on this forum.
My two suggestions for you for future purchases are as follows. First, see if you can see the fixture in action before you buy it, and see if they'll let you play with it at the same time. Two, before you do step 1, see if you can download a manual and/or see a preview video if the fixture in action. This step should help you narrow down selections or let you kick out things you for sure don't like it.
At least you seem to have a good grasp of what you do and don't want. That's a major advantage when it comes to light shopping. Too bad you made a purchase that didn't work for you, but I hope the learning experience gave you everything you need to help you move forward.