We call a LOT of methods in our system, if we can make calling them faster, it would make a difference.

In 5.10 you can deploy different method (lookup) resolution strategies. Download a copy of 5.10.0 and look at MRO (perldoc mro). You'll also find information in Class::C3. I have no idea if this will actually help you: you'll have to set up a testbed and try it out.