The jerky animation in the MZ00 clips is just key animation without the inbetweens, which happened often enough to be noticable in the waning days of the OAV. (You can see a lot of it in one of the Gal Force Earth Chapters, for example.) It could simply be that budgets and schedules were just crushing the life out of people and some scenes simply didn't make it across the finish line before the Yabba Dabba Doo whistle went off.  