Paralleling Power Supply Units Made Easy ???

While I've never done what your proposing I have built many many systems involving charging with solar. In these systems there are often multiple charge controllers providing charging to the same battery bank. They work well in parallel without any "tricks" in the programming. All are programmed to the same battery charging voltage and current limits appropriate for the battery bank. All do their job accordingly.
Power supplies may act differently but I really don't think it's even as difficult as you describe.