After some quick checking around on a line which is not mine, I would ask you how do you know they are brothers? I will concede this has been published since the 1850s but as far as I can tell there is absolutely no proof of this other than the same last name. I can’t tell you how many early English immigrants are called brothers based on a same name and have later prove to be false. Now with the DNA evidence strongly suggesting they are not brothers it would not be right to link them without further proof.
Second, how do you know that either of them is a son of Thomas Harvey of Ashill. The English ancestry is based on the will of Agnes Clarke of Ashill who “bequeath unto William Harvey the son of Thomas Harvey deceased, my kinsman, now in New England.” This is a great clue however there were three William Harvey’s in New England, and there is no way to know who the will referred to. William Harvey of Boston is said to the person in question; William Harvey of Taunton is said to the person in question – which one is it? An analysis of the problem by the well-known genealogist Mary Lovering Holman concluded that the William Harvey referred to in the will of Agnes Clarke was almost certainly William Harvey of Boston who married Martha Copp, and that this William was not the same person as William Harvey of Taunton.
Third, there is no such person as Joan Collier. If it is anyone it has to be Joan Colles who married a Thomas Harvye on 22 June 1612 in Ashill.
Maybe these questions are easily answered by someone familiar with Harvey research ( but I don’t think so). Until they are, rather than linking these profiles together, I would disconnect all parents from both William and Thomas Harvey, and also not link them as brothers.
Holman, Mary Lovering,. Ancestry of Charles Stinson Pillsbury and John Sargent Pillsbury. unknown: unknown, 1938.