I think that is the key point.
The key thing when considering team selections is not necessarily just getting the best 15 players on the park, but getting the best 15 for the particular game plan.
Not sure about this. Would Wales drop Shane Williams? He doesn't suit Gatland/Edwards mould of a back whatsoever, as they both prefer big backs and largely play crash ball moves with them, and Edwards has even said so previously. But they selected him (even though his defence is weak) because he is a player who can do things with the ball which is unique.
If the main thing you are using your wings for is tackling and chasing kicks (as I believe Argentina are), I don't see any issue with selecting Agulla and Camacho, as they seem very adept at these disciplines. If Argentina decides to play a more expansive game plan, someone like Imhoff will be ideal, as if given space he looks very dangerous.
Imhoff has played this game plan and still has done well though in spite of it.
Playing in the same game plan over the past year. Imhoff has:
vs England - made a break which possibly could have won Argentina a penalty
vs Romania/Georgia - scored tries
vs Stade Français - scored a try from the bench
vs Stade Français - scored another try from the bench
vs Australia - helped set up a try from the bench
That's more points created/scored than he cost from his defence (which was just that try last weekend), and more points contributed than Agulla and Camacho would.
I don't know why any side would leave out a winger who had done all that, for Agulla who has done nothing all tournament with ball in hand, plus has made his own try costing errors.
If the game plan is that the winger doesn't get the ball, then why has he consistently when given the opportunity done well from the bench?
And what does he have to do to get a start when he has done well for several matches in a row.
Whilst a game plan where the wingers get the ball in space more is obviously better for them, Imhoff is capable of making opportunities for himself.
As stated earlier, Racing-Métro also play a mainly kicking game with the backs not getting much space. Yet Imhoff has scored tries there. Look at this video of him playing Perpignan, not one of these breaks are created because his teammates have created it, it's because he has found the breaks.
Imhoff can still score in uncreative teams like Racing and may be able to for Argentina too. Look at his try from the second match against Stade Français.
http://www.youtube.com/watch?v=Q_YNUSl4HCY
Jump to 8:40, nobody creates it for him, he scores it himself with little space.
And despite his tackling issues, that is a technique issue not a strength issue. He is strong with ball in hand, watch this try against Castres again with little space.
http://www.youtube.com/watch?v=UXaUJK505NE
And of course he can score tries given space as well.
http://www.youtube.com/watch?v=SSddbsMm8Uk
http://www.youtube.com/watch?v=wNL4-JdVJ5g
Neither Camacho nor Agulla would have scored tries like them. So they're costing themselves points not having him on the pitch, his defence costing tries occurs less often than he scores them himself.
I agree with psychic duck with regards to the goal-kicking issue though. The goal-kicker, often more than any other player in the team, can have a massive effect on the outcome of the game, and given the tight nature of test rugby you need to have a top class goal-kicker. I'm not that familiar with all of Argentina's goal-kicking options, but unless they can get a kicker that kicks over 75% at international level they are going to struggle to win games in the Rugby Championship, as they are unlikely to be able to rely solely on try scoring!
Aside from MartÃn Bustos Moyano, Nicolás Sanchez is the other who has goal kicked as first choice at domestic level but he bizarrely didn't when he played against South Africa and they favoured MartÃn RodrÃguez (who barely ever kicks for his club Stade Français) who's kicking single handedly cost Argentina their World Cup match against England.