Burton K Wheeler
Moderator
Your best bet is to have enough Europeans survive the shipwreck to teach the locals how to ride horses, spin wool and make cheese.
Personally, I'd say that cattle are your number one animal, with any one barley, oats and rye for number one crop.
Number two crop is flax for linen; number two animal is likely sheep.
Horse and a second grain would likely be third.
The Mesoamericans and the Andeans did fine on the crops they had. European crops are useful, but not game changing, really.
It's North America that needs new crops to support large populations sustainbly.
I have seen it argued that the Haudenosanee (Iroquois) were mostly limited by clothing. That if you calculate the number of deer it takes to clothe them, it's a much, much better estimate of the max population possible than food.
So linen from flax and wool from sheep - or even leather from any domestic animal, could lead to a huge population explosion.
Also, the 'three sisters' arrive north quite late. If our introduction of European crops is 1000 or earlier, having a grain would be a huge advantage.
Also, manure for your fields to keep them fertile, so you don't have to move your settlement every generation or two. ANY animal would likely do for that.
I'd really like to see this clothing limiting population argument. Sounds novel.