McCormick isn't a "Branson Clone". The word clone, implies that it is a copy of a Branson design made by a different company. Branson and McCormick (and Century and some John Deere's and others) are all made by Kukje in South Korea. Same manufacturer, same tractor, different nameplates. Sort of like how a Chevrolet truck isn't a GMC truck "clone"; and a Cadillac Escalade isn't a Chevrolet Suburban "clone".
As far as the Kukje engine being a "version of the Cummins diesel engine" you are backward. Cummins uses a Kukje-designed and built engine with the Cummins nameplate for some of their smaller applications.
I have a 2015 Branson 3520H that came with an Ansung loader and I believe that some McCormicks of the same model come with a different brand of loader. I think that is because of some deal that the McCormick "company", which is a sub-group of Kukje, made with their implement maker, but the tractors themselves are identical.
This is common in the tractor world. A blatant example is Cabela's tractors, which are made by Tong Yang Moolsan (TYM) also in South Korea - Like the Kukjes. In fact in Late 2016, Tym acquired Kukje, so Branson, McCormick, Century, Kukje, Tym, Cabela's and even some JOHN DEERE... are all now made by Tym in South Korea. Some John Deere are also made by Yanmar, also in South Korea.
They're all good tractors. Shop around. Find a good dealer and make the best deal you can on a tractor that has the features you need. "Made in America" pride is dead. I guess we can still be proud of the fact that we invented the tractor in the first place; as well as the computer, and software, and pizza, and freedom, and baseball...