In BG3 sleep is 24, the average of 5d8 is 22.5. The fact it's guaranteed though means that 24 is MUCH stronger than 5d8. You know exactly what you're getting and full control over targets which is a massive massive buff. You can target the next enemy in initiative order so you absolutely know you can stop them acting. In a situation where there's a lot of grouped enemies and the one that moves next has more than 24hp it's not useful specifically because push is just such an effective counter. But there are situations where it's extremely useful because you can target specific enemies freely based on their hp and initiative order.
