I know the initiative starts when entering combat. My example were that the Gnoll at initiative 17 should have it changed when another initiative count brakes his initiative order. Otherwise (as seems to be right now), the Gnoll fails his save at Gale's initiative 10, and can make a new save on 17 next round. Therefore Gale won nothing on putting the Gnoll to sleep. It got 2 attempts to make the save. First on Gale's initiative and then on its own. I belive it should be a sleep from Gale's count round 1 to Gale's count round 2 and then make a new save. If the Gnoll makes that save then it should be able to act somehow but from that new init order (Gale -1).
In the very first dungeon we see, Dank crypt i think its called, my party sneaked up on the enemies behind the door with a lever. Gale cast sleep and 3 of 5 enemies failed there saves. Yet the other 2 shoved and everyone got up and attacked my party before anyone in my party could act. So that sleep spell, or hideous laughter or the like don't do what its supposed to do. Next time Gales just put a firebolt at the firewine keg and poof, 3 enemies dead.
This s a party game and alot more companions and pets can get value out of that one turn of sleep but that 1 turn is one round for the gnoll(if he doesnt get shoved before his turn) or whatever the debuff spell may be...
if anything the only problem is that spells like web and others do not force a check when enimie is standing in it at the start of their turn and that they can jump out of it without any rolls made that's the real kicker.. when it comes to debuff spells.
