Negative. I just tested again with both -cpuCount=2 and affinity 2 cores: 2685.51. Then I alt-tabbed and changed affinity to 4 cores: 2770.91. Alt-tabbed again 1 core: 1930.44
And yes, for the previous results I posted I shut down Arma2 and changed -cpuCount too (no reboot though). But I agree with you, there must be something wrong with the results. I also took a screenshot of the charts now:
4 cores (-cpuCount 2, affinity 4):
2 cores (-cpuCount 2, affinity 2):.
1 core (-cpuCount 2, affinity 1):