I cross-checked the manpower hours against our daily time sheet again, but it is still showing only xxxxx hrs.
Note the hyphen.
Use 'against' if you are comparing results obtained by two different methods of arriving at the result.
Use 'with' is you are merely verifying something by consulting another source eg checking an historical fact in two different history books.
(Hence, I am guessing that 'against' is correct in your example, since you are computing man-hours worked derived from calculating from time sheets and then comparing this with another figure.)
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