HO may appear mindless compared to stall but my opinion differs.
With Team Preview, you get the chance to look at all 6 of your opponent's team. You can then take a few seconds to try and identify the opponent's team's biggest threats, and then identify which of your own Pokemon you need to 'save' in order to deal with said threats. You need to identify which Pokemon you are going to use as a lure and subsequent sacrifice in order to find space to set up.
Just earlier I was battling a sand team. Obviously Excadrill was present. I knew he'd bring it out late game, so I needed to save my Keldeo, even though Tyranitar is perfect set-up bait for it. I needed to resist the temptation to switch in Keldeo and go on a little sweep b/c I knew in the late game he'd send Drill in and nothing I have could check it. In short, I used Infernape's Grass Knot to counter the Tyranitar, and his final Pokemon WAS the Drill, mine Keldeo, he used Ariel Ace, I use Secret Sword and win. The only reason I won that battle is because I was visualising the final stages of the battle, even though it was only the beginning of the battle.
There is nothing mindless about literally having to 'visualise' almost the entire game within a few short seconds in order to achieve maximum success with HO. And it's certainly not mindless compared to 'Set up Toxic Spikes, set up spikes, set up ST, use whirlwind, use roost, use recover, use protect, use roar'.
Whilst the same could be said about HO - 'Use Swords Dance, use Bullet Punch, use Bullet Punch, use Bullet Punch', the fact is, a skilled HO player needs to know when to use what sweeper, when to sacrifice it and yes, even when to SWITCH it. It requires a player to see the battle as a whole, it needs a player to look more turns ahead than any other play style.
Thus, HO requires as much, or maybe even more, effort as any other style of play; the only difference is it wins in less turns
