Stopped reading about there. The whole point of this thread is to ask if the requirement is reasonable, not to ask if they have the right to ask for it. Ofcourse the raid leader has final say on the requirements, but are they rasonable? That's what's being discussed here.
If that is what the raidleader and group is comfortable with, the yes it is reasonable. Asked and answered in my post above, but you stopped reading.
There is no right answer unless you know the players skill and usually if you know their skill they are not a pug, but someone you invited.