Dont pay attention to asymmetric vs symmetric. Pay attention to the cover and the balls listed purpose. People get hung up on what they think are factors but really are not.
Everybody had likely read or heard "asymmetrics just dont roll good for me" at least once Im sure. Now look at Track and some of their balls like the 503 505 508 607 706 ect. They have a fairly low MB rating/int diff of .003 .005 .008 .007 .006 ect. Many symmetric s when drilled, especially pin up or pin even with the fingers, will have MB rattings/int diff higher then the balls just listed. When you add a p3 or p4 xhole on many symmetrics you can get an int diff of .020 which is where many of the more aggressive asymmetric cores start.
You can also lower the MB rating/int diff on bowling balls depending on where you put the xhole.