I have just had a query (through the Tring Local History Society) about John Lake, born Tring around 1616, who went to America in about 1640. Usually when I get such a query I inwardly groan but in this case my answer was eased by the fact that the person asking the question was aware that there was much misinformation surrounding her ancestor's origins.
The problem I face with such queries is that there are many published family histories and family trees which lead back to the first settlers in America - and most of these effectively start with the arrival of the first settlers. In most cases there seems to have been few, if any, records linking them to their origins in England - and there has been an enormous amount of guesswork which has become "proven facts" by being repeatedly retold - nowadays over the internet - see The Dangers of Internet Genealogy and The Myth of Stanstead Abbey
Americans who have no experience of researching original 17th century American documents first hand, and even less about English documents and history of the period discover a published family tree going back to the very early days of settlement. They accept what is on the tree as being true and write to me thinking it is easy to match the possibly very unreliable information on the family tree with contemporary Hertfordshire records. They assume that because there was only one person with that name in 17th century America there was only one person with the name born in England - and assume that person must be their ancestor. In the case of the current query it turns out that there are there were four John Lake christenings in Tring in a two year period so Right Name, Wrong Body becomes very relevant.
In most cases I can do little more than direct them to My Ancestors emigrated from Hertfordshire and ask them to let me know what the possibly relevant information is available from American sources. The result is often that I don't hear from them again ...