It does seem silly but it is the best drill I have seen for upper/ lower half sequence. Mann/five posted the swingbuilder link a few days ago. I scrolled down and saw some dude laying on his back throwing discs and thought, WTH? Later we went to the cages, noticed lilly was opening her front shoulder too early and turning everything at once. I had her do the drill a few times. After the drill she started peppering the L screen instead of pulling the ball of the end of the bat.
I could be interpreting the drill wrong, someone set me straight if I am. I dont want to give bad advise.
For a hitter that is having trouble with the feeling of upper/lower separation, I think the drill has merit. I'm intending to give it a try with my DD. If your DD showed improvement after doing the drill, that's a good sign.