Regarding adjustable shocks and articulation... setting the shock to its softest setting, the shock adds no impedence to the speed of the upward/downward movement(articulation) of the spring. The spring is free to react immediately in accordance with the speed of forward motion.
If the shocks are set stiff... you're right, it does not change the maximum articulation up/down... but it will slow down the movement of the spring. If you picture rolling over some relatively minor obstacle with some amount of speed more than a crawl, the stiff shock will prevent the spring from compressing upward fast enough, and in turn roughly cause the frame to lift instead of allowing the spring to absorb the compression. So in effect a stiff shock can limit articulation by not allowing the spring to react fast enough.
Of course, if moving at a slow crawl over an obstacle, shock stiffness (within reason, appropriate to the weight of the vehicle) shouldn't matter.
My '71 CJ, with a 2.5" lift, with 9000s set on 1, rides smoother than a stock TJ on the trails... especially cruising between obstacles, say 2nd/3rd gear, low range...This is an opinion offered to me by TJ owners that have ridden with me or driven my rig!
So Jay... I'd still recommend an adjustable shock. Find the settings that offer you the best feel for your use.
JungleJeep, I just noticed you're SOA... a stiffer shock makes sense for that app. I'm assuming Jay is SUA, minor lift, softer or adjustable makes more sense for that app.