#They can all be woken up in one turn in the situation you describe
Creatures acting on the same initiative just means that the creatures all act one after the other. Otherwise, there is no difference in the turns and what they can do with them compared with any other creatures. That means each goblin gets an action and movement. If they are able to act, they can use that action to shake another creature awake if they wish.
Thus, if one goblin is not affected he can start a chain that wakes them all up.
However, do note that this implies that they are all grouped very tightly together with no enemies interfering with their movement or actions (opportunity attacks and readied actions come to mind). Additionally, they are all sacrificing their actions for the round, thus giving the PCs a big boost in action economy for the round.