There is no cost to having many small rules, and it’s very often a lot easier for us humans to think about.
The cron approach breaks down a bit though, if you might reboot your system. States are indeterminate until your next cron.
Having now got your initial functions working, you might look instead at a time-day-approach, where a rule system can divide your households day into chunks, and separate rules manage just what do during each chunk.
