If what you indicate is true, that would make the descendants of William "the Corpulent"/Jean McNutt Alexander related to those of us descended from John/Margaret Glasson Alexander, as that would make this William and John brothers.From my Alexander Record II records I noted that "John Alexander appeared to have an older brother, Robert, born Jan 30, 1687, and an older sister, Janet, b. Mar 14, 1689." Source: Christening Records, Glasgow,Scotland.I have no indication that Thomas Alexander had problems with any Rump Parliament.Not saying that he didn't, but it is much more likely he had problems with King James II (the Rump Parliaments were pretty much over by the mid 1660s).From wikipedia.com:"King James is best known for struggles with the English Parliament and his attempts to create religious liberty for English Roman Catholics and Protestant nonconformists against the wishes of the Anglican establishment. However, he also continued the persecution of the Presbyterian Covenanters in Scotland. Parliament, opposed to the growth of absolutism that was occurring in other European countries, as well as to the loss of legal supremacy for the Church of England, saw their opposition as a way to preserve what they regarded as traditional English liberties. This tension made James's four-year reign a struggle for supremacy between the English Parliament and the Crown, resulting in his deposition, the passage of the English Bill of Rights, and the Hanoverian succession."But even here, one must be cautioned that King James II was driven from power on Dec 11, 1688.Thomas had only been married in Mar, 1686; Rev Dr JE Alexander wrote that "Thomas Alexander was a prominent man of Lanark from 1710 forward..."Ergo, I'd say that he never went to Ireland.Don't know that as a fact, but I believe it was his son John & family who first went there--perhaps with William, if that was indeed his brother.As to whether the descendants of John and William are related, I'd say that William's descendants need to contact Roger Alexander or someone doing the dna research, as Bob Alexander of San Diego, Mike Epperson of northern Calif and I have all been tested.Hope this helps!