Ok, so it is working as (badly) designed then, if you prefer this wording. Irrealistic, and not balanced from a game perspective. It just blow out the current storage of the fledging settlement, for starter, meaning you'll get wastage in all what is stored, so tools, muskets, everything until you manage to remove part of the gargantuan stockpile they donated.
And then from a realism standpoint, I stand my point that there should be also a limit. Imagine seeing what amount to 100 IRL chariots worth of furs given by Natives to a colony size 1, sure.
Alternatively you might question why in the world they wanted to accumulate so many hundreds of tons of furs (plus the natives usually only hunted what they needed).
But the realism arguments are definitively not the most important here. That's more a question of game balance and game design.