The Mazal of Av

I am sure everyone is aware of the halacha that one should not go to court with a non-jew during Av. I was wondering how far this concept goes. For example, lets say someone has a salary review coming up, should one try and schedule it before Av? Another question that I was wondering about was whether this would apply to going to court against another Jew. On the one hand the reason for this halacha is that the mazal of the Jewish people is not positive. The mashmaos is that the non-Jew would win the court case not because it is a better time for non-Jews but rather because it is a bad time for Jews. That being the case, when 2 Jews go to court it is equally bad for both of them and they are on equal footing. However, could one argue that in a klaliyus sense it is a bad time time for the Jewish people, but in terms of how bad the mazal is for each individual, that is determined for each individual. Consequently, if you go to court against another Jew, who is to say that your mazal during this time isn't worse than your fellow litigant. (Although, you would also have the possibility that your fellow litigant has a worse mazal than you.)