Although the two concepts, the Longest Chain Rule and the Heaviest Chain Rule, imply slightly different concepts,  they have been used in the literature interchangeably without ending to too much confusion.

@Tangentc has a valid point about the infeasibility of faking a shorter chain with heavier workload because of timestamp inconsistencies, it is valid for long range re-org attempts though, in the short-range case it is feasible.

It'd be much better understood in a big picture approach:  generating fewer blocks in a large window of time inevitably causes lower difficulties to be set in the network and lower work loads.

Again, I'd recommend sticking with the security role of miners vs full nodes, instead of practicing endless controversies on irrelevant issues.