I agree it's immersion-breaking to see your party jumping around like superheroes. It also forces some non-intuitive choices, like choosing +1 to strength as the first stat upgrade for my Rogue, just to increase his jumping distance to get behind someone. Strength isn't supposed to be that critical a stat for a Rogue.
Unfortunately, it looks to me like the jumping distance is very tightly integrated with the scenery design. Not just combat encounter areas, but available travel paths outside of combat. Some areas you can reach now would be off-limits with a shorter jump, and reducing the AI's jump could screw up their programming. Larian may not be able to just reduce the jumping distance without completely re-drawing the scenery areas, so I suspect this is something we're just going to have to get used to.
