Drummond is better at everything besides free throw shooting. Drummond averaged 16 points and 15 rebounds and just turned 23. I would be surprised if Noel ever averaged that in a season in his career.
Not necessarily true.
With the contexts of both teams in perspective, it's hard to really compare the two via traditional stats. Drummond is excelling due to the 1 in, 4 out philosophy that SVG has mastered over the years, and that allows him A) much more space down low to operate, B) many more rebounds to gobble up down low, which has inflated his numbers a bit, especially his rebounding numbers. On the other hand, Noel played pretty much all of last year out of position at the PF spot next to Okafor. That both hurt his overall game and his rebounding numbers significantly, even though Noel is an elite rebounder himself. So going purely off of traditional statistics is flawed in this respect.
Further, even if his points and rebounds were better, though they were certainly skewed due to the system, outside of turnovers Noel is even or better than Drummond statistically across the board. He's a much better passer than Drummond with a higher BBIQ, and overall he's better defensively with better numbers in blocks, steals (and their respective percentages), and the fact that he's much more mobile and can actually switch off onto perimeter guys and be effective. In fact, the only thing that Drummond might be better defensively than Noel is low post defense against post-ups due primarily to his much bigger size.
So it's inaccurate to say he's better than Noel at everything outside of free throw shooting. I'd give Drummond the edge right now, but it's certainly a much closer comparison than you make it out to be. I bet Noel could average similar numbers in Detroit under SVG's system while making them a bit better and more mobile defensively.