Keep in mind we know very little about what is going on here. For all we know we will walk into a Hedgefolk encampment and the person in charge will present us the answer to the whole mystery wrapped up in a bow which they could not tell to anyone else because they are a proscribed group. Of all the people involved here the Hedgefolk have the least capacity to do anything about any knowledge they have so little power and few allies.
The Hedgefolk could have a solution of course, it's also very possible that a wood elf expert would have a solution. Depending on that, it's not too late to go see the Hedgefolk next turn.
And the same argument that the Wood Elves could have the awnser to the mystery straight away can certainly be done. And they too can't tell us because they are not there and not involved in the issue. If I had the choice of only one: flexing our elven allies to the Ice Witches, Boris and the EC and making contacts with Ostermark Hedgefolk, I'd rather flex.
Now, we might get the opportunity to do both, but if I have the choice, I'd rather go elf first.