With the 23-player matchday sheets, most teams will be seleting 6 props (both France and Wales have, at least), I think, three specialists on each side. Five could do, but you'd need two specialists on each side and one who can play both.
No they won't select 6 props in a 23 if that's what you meant; they will have two sets of front rows: 4 props and 2 hookers as they have done in European domestic competitions for a few years within the Union Specific Variations of the laws. This avoids uncontested scrums when 2 props are hurt; sometimes 3 are injured but that is rare.
Not even the French teams have 5 props in a 23 though they could do it once in a blue moon in the Top14.
This didn't apply to test matches, but in 2012-13 international teams also will be permitted to have 23 players in a match day squad. The additional reserve must be qualified to play in the front row.
But depending on the number of midweek games the Wallabies are playing they could take 6 props on tour instead of 5 as they had in 2010. Perhaps that is what you meant.
The weird thing is that SANZAR will not take the option of using 23 players with the extra front rower for Super Rugby in 2013.
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