Looking for information on Johann Schmidt of Pendleton Co, WV

I am looking for any information that you may have on Johann Schmidt AKA John Smith(b. 1774 d. Apr 1838 in Pendleton, WV).I am attempting to confirm information that I've obtained through several other online geneology sites, however some of it is conflicting.I have a potential father as being Heinrich Schmidt (Henry Smith) and grandfather as being Peter Schmidt of an unknown location in Germany.

I located a death certificate that lists Johann Schmidt and Catherine Simmons as the parents of Jacob Smith (b.1798 d.26 Jun 1869) in Pendleton Co, WV.

My confusion comes into play because every site I've looked at lists that Johann Schmidt was married to Mary Magdalena Simmons around 1794 - 1796.These same sites state that Mary M Simmons was sometimes listed as a Catherine Simmons (huh??).By looking at the Simmons side of things, I've located sites that list them as sisters born in 1752 and 1753 respectively.

Are these women sisters and Johann married one after the other died?Or is Catherine a second middle name and this is actually the same person?I would appreciate any assitance that anyone can provide.Much of the information that I've located has yet to be confirmed.Still working on it.