I'm not saying the South African openers have done any better. I'm just saying Sehwag has been made to look pretty ordinary, albeit by an excellent bowler like Steyn who has been good enough to exploit his weakness.
Now for Smith...we all know he has a god awful technique with that closed bat face. Credit to him he's managed to score a lot of runs despite that, but I'm just surprised more bowlers haven't found him out. Mind you it takes a lot of skill to exploit someone's weakness. Bowlers have tried to swing it back in to him, away and failed but Zaheer's got it spot on. Same with Steyn vs Sehwag....everyone knows he doesn't move his feet and a lot of bowlers have tried to exploit that and failed but Steyn's succeeded.
I think Smith's been lucky other bowlers haven't sorted him out, and likewise maybe Sehwag's similarly lucky. Thing is, one's technique is developed over years till they are successful. It can clearly be seen that Smith and Sehwag have techniques that can be exposed, but since it's brought them more runs than not, they've stuck with it. This isn't an open invitation to start slagging the Indian performance/Sehwag again, but he does need to improve his technique on lively tracks because it's during times like these that a traditional opener like a Gavaskar would be highly valued.
However, give credit where credit's due. The term flat-track bully is easily brandished but is it not important to win games in the subcontinent ? You can have a solid technique and all that, but if that means it results in you not having as much of an impact as Sehwag can have then perhaps that needs to change too. Why haven't other players smacked a strike rate of 80+ with an average of 54 in India ? The way he turns games on his head is incredible ! India's win against England in Chennai comes to mind for an example. Having a solid technique is well and good, but if that means you don't strike at 80+ with a high average in India then simply put, you aren't as good as him at home. He's arguably the best player in the subcontinent, and he may not be as good as that away. But then I guess you can't have everything.