For a long time I never understood the prevailing opinion about the inherent incompatibility of the game lines in WoD because I mixed them up all the time. But now thinking back on it I realize that I never really needed to use the rules, like for combat, between the types. I don't know if it was the stories I ran, or the people I gamed with, but interactions were either cautious curiosity, or abject avoidance ("Oh shit, werewolf! Run!!!")
Well there was that one time in live when my Toreador fought a lupine, and that went fine. Idk, maybe the live rules were designed better for that?