When I researched Scarffe a few years as my "warmup" before tackling Gelling, I ran into the exact same problem. There already is a John b 1794 alive and well, so the 1809 John can't be right. The mother Jane Hogg, though 10 years since her previous child Thomas, was 44 in 1809 so she could have had a late child. My notes say "serious problem here; need to check original records."

John, I could send you a chart of what I have for Scarffe but would need your email address. I had trouble making some connections, so it would be good to have someone critique it. Our common ancestors would be John Scarffe (ca 1690-1742) & Margaret Quark (d 1760) of Ballaskerroo Lonan.