Say 4 goblins ambush a level 2 party, everyone is surprised but the Wizard decides to use his Portent feature to influence the initiative roll of the enemy. One of his portents is a natural 1, and he uses that die to replace the initiative roll.
Do all 4 of the goblins' initiative change to 1 or does just one goblin change?
Here's what I got from a reading of the PHB:
... When combat starts, every participant makes a Dexterity Check to determine their place in the initiative order. The DM makes one roll for an entire group of identical creatures, so each member of the group acts at the same time...
Emphasis mine. Reading the bolded text, it seems that in cases of identical creatures, Portent can effectively cripple the entire initiative of the opposing team.
However, when you read the first sentence, it seems that the entire group shouldn't be crippled by a single portent roll as each creature should be rolling separately and the bolded text really just says, "hey, don't waste your time on rolling for each goblin. Just roll once and they all go together."
A big factor of my hesitance to rule on the side of the first interpretation, is that it seems too overpowered for a 2nd-level feature.
So which is which? Am I missing something?