Indian Influence on Founding Fathers?

Recently Betsy had a post about the possible influence of the Iroquois Confederation on the Founding Fathers and the writing of our Constitution. Betsy seems to posit that there was no influence. While I agree that the main theoretical basis and inspiration for our Constitution comes from John Locke, Adam Smith and other European thinkers - I have to think that the example of the Iroquois had to have had some practical influence.

In 1754 Benjamin Franklin came up with a plan of confederation among the colonies that became known as the Albany Plan. This plan used the Iroquois Confederation as an example and was in response to dangers posed by the French and Indians along the frontier of the colonies.

According to Walter Isaacson's biography Benjamin Franklin: An American Life this is what Franklin wrote when formulating his Albany Plan:

"It would be a very strange thing," he had written his friend James Parker in 1751, if six nations of ignorant savages [the Iroquois] could be capable of forming a scheme for such a union... and yet that a like union should be impracticable for ten or a dozen colonies, to whom it is more necessary."

Maybe no single issue united the colonies more than the passage of the Stamp Act. In response to the Stamp Act, representatives from nine colonies met in New York in October of 1775. Again from Isaacson:

The motto they adopted was the one Franklin had written as a cartoon caption more than a decade earlier, as he sought to rally unity at Albany: "Join, or Die."

While I think it is clear that the framing and final finer points of the Constitution are clearly the influence of Locke, Smith and other European thinkers - I think it is also clear that the example of the Iroquois was there at the genesis of the idea of uniting the colonies under a single Constitution. What is the harm in acknowledging this influence?