I'm not sure if 3-4 times a day is a lot. I had computers (especially laptops) which were way more aggressive with spinning up and down the disks. Maybe you can look it up. A decent (enterprise(?)) hdd should have some datasheet available including info about how often you can powercycle or spin them up/down.

And I wouldn't wake up disks deliberately. If you don't mind the 5-10s waiting, you can just spin them down at the end of the day and leave them that way. The next day they'll either spin up on first access, or they won't. And save that one cycle. I'm not sure though if you can change the spindown timeout during the day without also waking it up. I mean you could run a script that spins them down at 22:00 and sets the timeout to 1h, and at 07:30 you run a script to keep them awake for a 6h period. But you'd need to test if changing that setting wakes them up. Or I'd rather not run a script like that. Sometimes executing hdparm spins up a disk, even if unnecessary.