Aces High II works fine with multi-core CPU's. There has never been a problem with multi-core CPU's back to the original HT enabeld Intel CPU's. Aces High II is one of but a few games which is actually multi-threaded and has been multi-threaded for quite some time.
The problems with the dual core AMD CPU's had to do with a problem AMD had, which was corrected in a patch.
If the game had a problem with multi-core, it would have shown up years ago in the Intel HT CPU's. The problems AMD had to do with the use of the high resolution timer when using threading. Anything would have blown up using it. It was not an Aces High II issue.