Earlier quoted context omitted.
Doing the motion first lets you visually confirm the range before invoking the command. You also have the opportunity to adjust the range if you didn't get it quite right. Mnemonically the vim order works better for English but in practice I find the visual feedback from selection better for anything even moderately complex. An example would b `f` or `t` since I tend to hit the letter I was aiming for earlier than I…
I have never felt the need to visually confirm something as obvious as "delete 1 word". On the other hand, you cannot do something like "delete 3 words" in kakoune. "3wd" just takes you to the third word and deletes that. Deleting 3 words is definitely slower. And it's kind of infuriating... What am I doing wrong?
That is, counts work, it’s the movements that are slightly different. See manual §3.4–6[1].