As Matt said, The Mixed Breed Pearl is a completely different animal. Being a Z-spin asymmetric, it is very different from the Gladiators. Depending on how you drill a MBP up, it can be very tame or stronger than anyone should need. But you do need to know how to drill it. As I understand it, this ball came out when USBC was thinking about limiting how far you could put the CG off the grip center. The intent was to do away with the "exotic drillings" and basically make everything a label drill. The way the ball was designed, you actually want to put the pin over the fingers, the CG in the palm area, and your thumb hole directly on the "V", which marks the true mass bias. This will make the ball as tame as you can make it, as the ball will be "dynamically symmetric" with no preferred spin axis. Guys who really come around it with a high RPM love this, because the ball can't "jump". Guys who come up the back or are "RPM challenged" hate it, because the core won't give them any help. But the beauty of this design is that you can add an extra hole in the "double thumb" position and make the ball as strong as you want. Start with no extra hole and see what it does. If you need more reaction, start with a small diameter hole and see what that does. If you need more, gradually increase the size of the hole until you get what you're looking for. It is really an ingenious core design in that it allows you to make some rather substantial changes to drilled ball specs (and therefore reaction) after drilling. It would be best to start with some thumb weight (maybe 0.50-0.75 oz.) and maybe just a touch of side weight. That way the ball will still be legal with no hole, but give you some adjustment room if you need to add a hole. You can also make the finger holes deeper to offset a balance hole if needed. You can also follow Matt's instructions. Matt's method fixes the preferred spin axis by using the mass bias, the other method actually creates the preferred spin axis by using the balance hole.
However, since the Mixed Breeds are now discontinued, you may have an issue finding one with the specs you want. You could consider two of their current balls; the Raven Invasion or the Samurai. Comparing the Raven Invasion to the Gladiators, it is a symmetrical with a bit higher RG (2.53 vs. 2.51) and a bit more differential (0.049 vs. 0.044). The Samurai has the same RG, more differential (0.050 vs. 0.044), and the same intermediate differential (0.007) that the Gladiators had. Although I don't have a Samurai, I have thrown the Invasion. Very clean through the fronts, didn't pick up in the mids quite as early as the Gladiators, but a nice hard arc (just a touch sharper than the Gladiators) in the back.
One last option you might consider if you have access to balls that have been discontinued is simply to pick up another Gladiator and change the surface. You could go from the 2000 Abralon box finish to 3000 or 4000, or just add some polish to the box finish.
A long post, but hope it helped.
