I had doubts about the Forsythe link at the time because Sgt. John Dochstader's wife Catherine also seemed to fit the profile ( e.g. Delaware, Sgt. John's property left with the Dennis family, 'relatives of his wife', etc ) and because the Catherine in Ezekiel's will of 1803 has no last name and no Forsythes are mentioned; Daniel and Catherine Forsythe's children were born between at least 1796 and 1809, so this Catherine was married at the time the will was written. In any case, though, Dochstaders aren't mentioned in the will either, and Sgt. John of Cayuga would have been married to his wife for going on twenty years by then. A Forsythe family connection seems just as possible since a James Forsythe, killed during the War of 1812, left his children in the care of William5 Dochstader (Henry4, Henry3) and Hannah Dennis (William, Ezekiel), and the incident on its own links all three families.
I remember the name 'Julen' from a legal document of some sort, I'm pretty sure it was Ezekiel's will but maybe not. Also, "Long Point" (Norfolk) in the preceding post should be "Point Abino" (Welland), I've got my locales mixed up.
The Delaware reference is for Ezekiel's son William who married Sarah Anderson and was the father of Hannah Dennis ( who married William Dochstader ) and brother of Catherine Dennis ( who married, probably, Daniel Forsythe ). I think he is listed as being Delaware in band council documents in David Faux's book, and it's these docs that imply that the Dennis family matriarch ( Julen / Julia ) was Delaware. Factoring in also that Sgt. John Dochstader's wife Catherine is listed as Delaware in his petition, and that he'd left property with the Dennis family, "relatives of his wife", I would take all these Dennises to be part of the same family. Whether Catherine who married Sgt. John was actually a Dennis or e.g. related to Ezekiel Dennis only by way of his wife ( which the Delaware reference might suggest ) I'm not sure. Interestingly, Catherine and Sgt. John4 Dochstader's son Henry5 was one of three men implicated in the 1814 murder of William Francis, on whose property in Walpole was living a John Dennis and family, who seems also to have been a relative of Ezekiel.
Miscellaneous Dennis documents:
From the info I'd guess that the right Ezekiel Dennis ( born about 1725, died 1803, married Julen/Juley/Julia, resided Point Abino ) is Ezekiel4, Joseph3, Jonathan2, Robert1 Dennis, and that the other Ezekiel of Upper Canada is his nephew, Ezekiel5, Joseph4, Joseph3, Jonathan2, Robert1 ( born 12 JUN 1753 Chester Pennsylvania, died 1810 Upper Canada, married Ann Heacock, resided Clinton Twp ). The writeup for the first Ezekiel, born about the right year, living in the right place, and with the right name, is
"EZEKIEL DENNIS2 (Joseph1), son of Joseph Dennis, probably accompanied his parents to Bucks County in or about the year 1738. He accompanied or preceded his father to Wantage, Sussex County, New Jersey, where he was appointed to the court on 5 mo. 30, 1754, Overseer of the Poor for the district of Wantage. Charles E. Stickney, the author of "Dennisania," thought that Joseph Dennis resided during the later years of his life with his son Ezekiel. We have no record of his marriage or family."
( http://freepages.genealogy.rootsweb.com/~buckscounty/EarlyFriends/earlyfriends_dennis.htmlhttp://freepages.genealogy.rootsweb.com/~buckscounty/EarlyFriends/earlyfriends_dennis.html )
Ezekiel of Point Abino's oldest son Obadiah was born about 1754 so that works. If Ezekiel married a Delaware woman then I don't know whether it will have been recorded in the usual Quaker records. The "Friends in the Niagara Peninsula" article states that "Nathaniel and Obadiah Dennis [ his sons – no birth recs in NJ Quaker records ] came from Sussex County, New Jersey and settled in Humberstone", so Ezekiel would probably have resided Sussex County from at least the mid-1750s through to the time he went to Home District, and would probably have met his wife there too, the Delaware being indigenous to Sussex County NJ. Sussex and Warren Counties are the worst places in New Jersey for genealogy, New Jersey in turn being the worst state to have to do genealogy in, but it's conceivable that if you find the right references to the right Ezekiel then you can find out who his wife's parents are.