[css3-flexbox] 'flex-order' vs. 'flex-index'

There is an issue on naming of 'flex-order' property that we didn't get a resolution for at F2F:
http://dev.w3.org/csswg/css3-flexbox/#flex-order

I propose keeping flex-order. I think it is better because

*         Z-index is "position on Z axis", or "value of Z".  It could just be called "Z" but it probably isn't because it is integer.

*         Flex-order is order of processing. It is not "index on flex axis" or "value of flex"

*         Keeping the name "order" directly points at the fact that flexbox reorders its children for all purposes.

Any arguments in favor of "flex-index"?