Currently there are two modes of carrying objects - pick up(for item) and grab(for objects).
IMO there is something lacking - single clonk pushing a bridge segment is a bit unrealistic. I think, that there should be three modes instead of two:
Pick up - as it is now, for very small objects.
Grab - for objects like trees, and wheeled vehicles.
Carry - Each object would have few vertices defined, and player could select one clonk, walk up to lets say - lorry, 'grab' one vertice, walk up with second clonk and grab second vertice. This way all clonks from same team grabbing an object will follow movement of selected clonk, and this would allow few clonks to pick up a tree, and carry it over a gap in earth(tough not too big, as their jumping would be limited by weight of carried object. Also it would allow to pick up unconscious clonks and carry them to base. Sometimes with lesser objects even a single clonk could carry them.