a cross product of some vectors is supposed to be perpendiculkar to all of them and have lnegth equal to the volume they span, and be right hand oriented.
So if you want there to be only one such vector, you need to start with a product of n-1
vectors in n space. that's why you can multiply 2 of them, only in 3 space. in 4 space the cross product of three vectors makes sense.
But if you are willing to have a product which is more than one vector, maybe some kind of block, you can do it with fewer.
david bachman's book gives a nice treatment of the geometry of this subject.