I have a relative, born in Canada in the 1820s who for some reason moved to southern Missouri in the 1850s. It seems a little unusual to me and, at this point, I do not know the reason why he moved. What I do have a reason for is why I know it is the same man (his name, year and place of birth and the names of his children all match).
If you don't have the reason for why your ancestor did something a little unusual, try and make certain you have good reason for believing it is the same person. Maybe the reason it seems like you have the "wrong person" is because you do.