I'm pretty sure Podolski, Theo and even Bendtner could play CF to a decent enough level, but obviously several levels below the best in the business like Suarez or Aguero. But by the same logic Caz/Ozil can play nowhere near the level of the best wide forwards in the world, in fact they play the role completely wrong. Let me be clear, we both already agreed that a striker is the priority, I'm just using that to make my point.
For me Caz/Ozil don't play in the wide positions 'convincingly'. I would put them in the same group as Rosicky, Ramsey and Wilshere because, although they are better at it than those three due to their skill on the ball, they still fall into the same patterns of CAM play in front of the opponents rather than playing on the shoulder of their defence, running at and beating fullbacks and giving us a variation of play. They both do exactly the same thing the three CMs behind them do and It's all very slow and predictable. The fact that Wenger has consistently brought in the same type of player to play in those positions in the last eight years really grates - Hleb, Rosicky, Nasri, Arshavin. None of them were successful apart from Nasri to an extent, but even he played in a central position in his best season for us.
It's all about balance. I remember seeing Messi go shoulder to shoulder with Vidic, beating him off, staying on his feet and keeping the ball. He can pretty much do that to anyone and he's 5'6 and not particularly well built. I'm not sure what you think of Reus but he's definitely not a lightweight and height has nothing to do with it. And as for the pace, he comfortably beats both Suarez and RvP in that department.Suarez and RvP are tough boys. Anyone who has met RvP will tell you he has quite the stature and is 6'2 whilst Suarez has great balance, but also great strength and is constantly willing to knock anyone in the ground over to score, be it the opposition, the ref, the goaly, a little girl in the stand.... Anyone who points to Aguero or Tevez would be completely missing the fact both of those guys like Suarez give as good as they get and more so and both are powerful players. I've seen the pair of them regularly knock over defenders twice their size. Without that power they would be ineffective in that position and that is despite their ability as footballers.
The wide left position is probably the best served in the squad with Podolski, Cazorla and Ozil all able to play there so I am a little surprised quite so many would spend whatever it would take to sign Reus and playing him left or even more unbelievably CF.
So why get him if we have players that can play there? The same reason we want a world class centre forward - he's a hell of a lot better than anyone we already have and would improve us significantly in an area we are weak in.