With the i7, you have four physical cores and four logical cores.

I've tried all eight cores on all five games.
And a lot of combinations of some cores here others there.

I get the best performance with the four physical cores each assigned to all five warcraft sessions; ie, allow Windows to determine which games need what amount of processor power.

Surprisingly, having none of the logical cores assigned to any game is better performance (only very slightly) than having logical cores assigned anywhere.