If I have understood you right you're also a teacher, right? Aren't you teachers helping each other with making exams? For example, when I was in High School the math teachers for one calculus course usually made the exam together and then handed it out to their respective classes, then they corrected the exams together as well.
Both because it'd make it easier with the creation of the exams, but also because the correcting would be less biased.
We do that sometimes, but not all of the times. I make my own exam questions in Intermediate Algebra while I ask the Elective Geometry II teacher some of her lessons so that I can incorporate my questions with her.
Of course we have our own sets of exams to check. I check my own exam while he/she checks their own. We just coordinate each other but not totally help one another. We just make sure that some of our lessons intersect at one point.