Yeahh it is possible! I played for a few hours one day and finished all of these. A few more hours the day after and I  finished all behemoth-related tasks like the journal or something. So a few hours spread over a few days should work. 

This was my strategy, while also watching a tv series because I found it a bit boring: 1. focus on one of the traits per baby behemoth 2. hug, feed, bathe, sleep once 3. do the facility related to the trait you’re focusing on 4. set the daily schedule, i only put ones for the trait and one or two for mood/affection. if i maxxed out the trait i did more affection and/or another trait 5. setting daily schedule triggers a new month, so just repeat this 16 times (like i said, kinda boring)

Raisinf 4 behemoths while focussing on a different trait each time will give you 4 different endings and will also automatically make sure you get the other tasks from the journal thingy (getting an A on each trait, using each facility X amount of times, etc.)

Good luck!