This can be done as you can place fields from two tables on the same layout as long as you have a valid relationship linking your two tables.
However, there's a simpler approach that may be worth using: Simply define both fields in the same table. You can still script your check and it will execute a bit quicker if you are working with large numbers of records. (A script may not be necessary as their are validation rules you can set up to make sure the entries match.)
It seems to me that instead of a validation, you would want a flag.
Put both fields in the same table (Say FieldA1 and FieldA2)
Have operator 1 use layout #1 with only FieldA1 on it.
Have operator 2 use layout #2 with only FieldA2 on it.
For the overseer layout, have both fields next to each other along with a third field (FieldAflag) which is set to a calc:
If (FieldA1 = FieldA2 ; "" ; "Discrepancy" )
Repeat as necessary with Fields B1, B2, C1, C2...
But the best way would depend on the use of double entry.
In my experience, any discrepancy should be reviewed by a third party, but that's in my rather limited field of experience.