Most stronger hybrid balls are asymmetric now. In fact, most of the strong balls are asymmetric.
A couple of the stronger hybrid symmetrics are :
Hammer's Arson handles medium-heavy oil and is, according to Hammer, 60% pearl and 40% solid.
Lanemasters Sting Widow Maker is a solid/pearl hybrid that comes lightly polished.for medium oil. If you dullled it to 2000 or 4000 grit, I am sure it will handle lots of oil.
Storm's Reign Supreme and Hyoad are also hybrid symmetrics. Both come polished. Sanded to 2000/3000/4000 grit and they would be stronger than the Dagger.
Heck, sand the Dagger to 2/3/4000 grit and it will also be stronger than the polished Dagger.
"None are so blind as those who will not see."