I'm finding the same mistakes myself while reviewing. I think there is some confusion for keyers regarding the hire date and using the continuous year date instead of where the wiki card examples are saying to key the records. I think once that is cleared up or stated more obviously, there wouldn't be as many errors being made.

I'm also running across keyers pulling Employment Location and Occupations where the Hire Date is instead of following the Wiki instructions and pulling from 'Present Occupation' or 'Where Now Employed' and then expanding the full occupation, city or state when it's abbreviated. (Ex: Card just says Chgo, Keyer puts in Chicago, Illinois or Sec Labr and it's expanded to Section Laborer)

Also getting a lot of pension records being keyed wrong but that's another topic for another time ;)