Think about every Reds vs Waratahs game.
The Waratahs have had good jumpers but been destroyed. Luckily it's super rugby and they were able to make up for it. In test rugby can you give up one of your best pieces of attacking opportunity?
In order to have a strong defensive line out it's important too. The reds had Australia's best line out for stealing throws. They stole 27 line outs. That's because they really had 5 jumping options, with 4 of them all stealing line outs. Thomson stole 9, Horwill 6, Simmons 5 and Schatz 2 of those 27.
I'm not advocating the Reds players here (especially not Schatz) or what they've done. But I'm saying if you want a strong line out in attack and defence, you need multiple quality jumping options.
Perhaps your example conveniently illustrates my point in advocating for Vaea at the back of the scrum.
Yes, the Reds did indeed have the superior lineout, yet it was nullifed by a weak pack that included a litany of test harden players. For all good it did, they were unable to exploit their lineout advantage.
If this format is repeated in the wobs starting pack, especially as your proposing a defensive line out, it may reproduce the same outcome.
Cheikaball is not defense-orientated. And if he is unable to coach out the skeletons of recent wobs rugby (i.e. mental weakness), there wont be a fairy tale end. Therefore, Cheikaball at the wobs, as it has been at the Tahs, must be bold and confronting.