Namestnikov per 82 games for his career: 36.9 points
Miller per 82 games: 43.2 points
Just by their career averages, this is what they'd be classified as if we took last season's PPG averages. Miller's career average would've resulted in about 155th last season, which is a low end 5th forward. Namestnikov's career average would've resulted in about 193, which is a high end 7th forward.
155-5th
193-7th
But I think its important to consider that if you take Miller's PPG average the last two years combined where he's clearly playing improved hockey, of which only 19 games came with the Lightning's great forwards, his average is about 84th, which is a low end 3rd forward. Thats a first liner. Some will claim thats partly due to playing some games on Tampa, but if we take away his Tampa stats, he still comes in at 114th, which is about one forward slot higher. If this guy isn't a first liner, he's very close to it. If we consider Namestnikov's career not counting the games he played this season for Tampa, considering he played on a line with two elite NHL'ers, he comes in as about 251st, which is a 9th forward. And I think thats what the guy is.
84th
114th
251
Thats before we even consider other parts of their games. Miller is a much better defensive player. I don't care what the corsi stats say. I've watched both of them play enough to say that Namestnikov plays very soft and has a low hockey IQ. He can't play center either. Miller certainly has his defensive issues, and its fair that he had a falling out with management so they wanted to trade him. But he is not soft, he plays a lot more physical than Namestnikov, he can play center better than Namestnikov, and at least his defensive issues are coachable. His defensive issues are trying to do too much. When he doesn't do that, he can have some very effective defensive games, evident by his usage on the PK for two years now. Namestnikov is just a bad defensive player. You aren't coaching the soft and bad hockey IQ out of the guy. The best you can try to do is limit his defensive responsibility by putting him on the wing, and asking him to just be an outlet guy who carries the puck out of the zone.
I don't think its a stretch to say that Miller is a low end 1st liner, and Namestnikov is a low-end 3rd liner. If we want to quibble and say Miller is a good 2nd liner, and Namestnikov is an average 3rd liner, go ahead, but I don't think there's much more of a realistic case against what I'm saying than that. Miller is a considerable better hockey player. Its not even close.