I agree. I think the word interlace would be clearer. http://dictionary.reference.com/browse/interlace

Please don't use the term "shuffle" which insinuates you want a random shuffling of the combined arrays. I'm new here, so now I see that the unit tests given were indeed looking for a specific order and I was thinking it was an example. Instead maybe re-word it to say something like combine to the two arrays so that they return this sepcific order, etc...maybe its just be but the term shuffle confused me :)