Of course I understand and thats no problem. If I have done this correctly my character came to the MoM when he was 18 and retired from there when he was 35 so he was part of the Auror office for the back end of the Voldemort Era. So realistically he never could have joined the Order of the Phoenix anyways so that works just fine. An realistically speaking he would have never been at the battle of hogwarts because he was still rather new into the Auror Office, so at best he would know things about the Voldemort Era but he would have never been directly linked or part of it.