The box will use the fastest so as far as I know they can go in any order.
But, so you know for sure, try it both ways around and see. Then report back and let us know you findings please.
By giving reports on tests you do helps prevent myths which go on for years and no one has ever actually tired all the options. (I am not saying they haven't but you know what I mean)
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Just re-read, I think he just means put is under the current one as that is where the next free line is. Just how I read it.