Here is exactly how the drawings were staggered. There were 9 drawings to the stagger, 437 thru 453 (using odd numbers only.) For clarity, let's give them the letters A thru I instead. For the smooth version, shown in Part 2, they were of course shot straight through: A-B-C-D-E-F-G-H-I, and exposed on 2's.
But staggered as you see here, and exposed on 1's, it goes like this: A-B-A-C-B-D-C-E-D-F-E-G-F-H-G-I-H. That's 17 frames as compared to 18 frames in the smooth progression, so the screen time is almost the same. The basic idea to this stagger is: advance two letters, then go back one; advance two letters, then go back one. Thus you progress steadily on to the end.
In my opinion the stagger adds an extra element of effort to the action, and was well worth doing.