That Renegade also has a different front axle, look at the Warn lockout. It probably has a Ford front and rear axles. Can't see much of a hub or another lockout in the rear wheel. So, that Renegade has gone through some driveline changes.
Flex is good, but if you don't have a properly 'geometric' (if there was such a word) vehicle, what good is flex? If that Commando had the articulation, but was on 29" tires that were on a 3' track width and it still had the 103" stock wheelbase, then what good is the flex. He'll be flopping it all over the place.
Flex is part of the design and layout of the vehicle. Some owners enhance the flex to be capable of driving on their trails. In some instances, it good to have, others not so good. It's a compromise on how much. Leafs can be designed to flex well, but then it's also in where on the frame they attach. The shock is the most limiting aspect of the suspension which limits flex. Most stock shocks only travel 4-5", if that. Aftermarket boosts an additional 1-3" for a 3-4" lift. But if you research properly, measure and locate a shock properly, then your suspension could be designed and laid out to work with the frame, tires, track width, weight capacity, etc of your vehicle. Most owners, I'm one, use the aftermarket to come up with those constraints and work out a suspension lift. It's not rocket science, but there are a lot of factors to consider, quite a bit vary in their numbers.
