Well, you've certainly contacted a Latimer from Canada. There are really quite a few Latimer families in Canada. Only a very few are related to my Latimers as far as I know. There are a couple of young American women digging into their grandfather's history and he lived in this area, Simcoe County, Ontario. He was also a William Latimer, but remember that the Latimers were mainly Heugunot (Protestants) and in Ireland a great many of them were named William. My William was born sometime in the 1830s, moved to Canada in the 1850s and then went to the US.
There are still many Latimers living in Ireland, North & South, to say nothing of England, Scotland & Wales. Somewhere, I suspect, there is a common link but it may be a long way back.