*shudder*
I can imagine the game meeting on that one:
Dev1: "Hey, ninjas totally make my pee pee hard, lets have them as a playable class"
Dev2: "sweeeeeet. Hey, how about we put in some Norse babes with huge assets ans small armour?"
Dev1: "Woh! That'd like totaly rock, yeah. Vikings kick ass, especially if they're female and not wearing enough armour to protect a small mouse"
Dev2: "This game'll rock"
Dev3: "Hang on, the classic idea of a ninja iis mostly based on the activity in 15th and 16th century japan, while the valkyrie is a mythical angel style charicter from norse mythology. That'd be 9th/10th century and earlier. Given the game has a classical European fantasy setting arn't ninja's out of place? At worst they cheapen the setting of the game by simply latching onto the current culteral facination with japan?
Dev1: "Like STFU dude, ninjas totaly rock. Dont make me flip out and cut your head off"
Dev2: "Yeah loser. Go get me a coffee"