The worst offender was indeed the Protoss Dragoon and the Terran Goliath. But fun fact, their specially awful pathing was due to the fact that both those units CHANGED SIZES WHILE IN MOVEMENT, to match their moving animation, making them not fit on arrival to a place they did fit on departure.
I'll leave this here, for the ones interested. It's from the guy that worked on the Starcraft pathfinding code: https://www.codeofhonor.com/blog/the-starcraft-path-finding-hack
Jo, it wasn't just the Dragoons, though they were pretty bad. Goliaths also had a... special place, in the pathing system. https://www.youtube.com/watch?v=90K_G4hyxCk