I think he just means split them repeatedly until all of the nucs are small. A nuc on 4-5 medium frames should be pretty gentle, so depending on how big your hive is to start, you may need to 'split' it into as many as 6 or more nucs to get them down that small (assuming you are starting with a full-blown, 30-medium-frame hive).
-fafrd
p.s. I believe that shaking a hive out is only something you consider to do in the case of laying workers...
