Can say nothing to the Druid spells as I never played one, but as Sleep does work guaranteed without a saving throw there should be some countermeasures. The woken up creatures lose their action, if the one who wakes up would also lose the action by doing it, for me the spell would be probably too strong. I see it more of a problem that some races are absolutely immune to Sleep (although I'm always playing such a race).
The problem here is rather that the spell is completely fixed. In dnd, you throw dice to check hp points. Usually it comes out average, and if you threw out a little, you can not even neutralize a goblin by wasting a cell. About the fact that you waste an action, well, this is to be expected, it's not an ordinary conspiracy, but the spell paralysis is even stronger there you can beat the enemy as much as you want. And you don't always lose your turn if an ally moves earlier on the initiative, then only he will spend the action. You can also wake up damage, for example with magic- 2 missiles at the enemy and 1 at the sleeper. This spell works normally only at the beginning, then the opponents will be so fat and almost everyone has a hard 1 resistance, so you'll distract the insects while you kill the main enemies.. although they still made 2 moves instead of 10.
