Since you asked so nicely, here are the combined career per 48 minute stats for each group:
Year MPG FG% 3P% FT% RPG APG SPG BPG PPG
Spain 93.6 53% 24% 73% 12.4 3.0 1.0 2.9 20.7
Brazil 70.2 55% 5% 64% 12.6 2.5 1.7 1.4 18.2
I'd hardly call that in a different class.
ETA: The formatting for the table is a pain in the neck, sorry I couldn't get it to set up nicely.
The formatting on the chart looks good.
I just dont think you can pull the per 48's because its judging off minutes per game that these players didnt play for a reason. Nene and Varejao have had injury problems and Splitter is a back up right now because he sits behind the best player on the team. Gasol brothers have been consistent producers and Ibaka is more of a defensive stopper.
If you look at what the brazil 3 actually have done in their careers (im choosing Points as the easiest metric), Varejao is around 11 points a game (his first of 8 years in double digits), Splitter is at 9 points a game (which I will give you that it doesnt include the European part of his career and Nene is around 14 points per game (I used 2011-2012 since these are the most recent stats and the career stats would only lower the PPGs)
Based off their consistency and actual contributions Marc Gasol made the all star team this year, Pao is consistently among the top centers in the league/ (top 30 producers in the league- to be generous). Ibaka led the league in blocks.