Ability to "carry" large objects is easy to implement. And I think it's a pretty good solution. Right now barrelmancy feel more like an exploit then game feature.
Having "grapple" as a combat mechanic would be cool. But it's much easier in a make believe. Imagine amount of animations it requires. DnD has hundreads of creature types, and each combination will need its own animation set for initiating, holding, and breaking grapple.
