The processors property is marked as private and Cmd's optimizer takes advantage of that to streamline the class processor steps knowing that all required classes have been ordered ahead of the classes that need them. This of course presumes that we also know of all processors.
Be aware that use of private API's is not supported nor are they guaranteed to remain as they are currently defined - they can change even in minor/patch releases.
In Ext JS 5 we are making onClassExtended and onClassMixedIn public so that you can extend class semantics in safe ways. See http://docs.sencha.com/extjs/4.1.1/#...nClassExtended for an example. We have some other enhancements in this area for v5 but these two methods have existed since 4.0 and just not been declared as public. These are being made public because folks have asked for a supported way to extend class declarations (that will also work with Cmd optimizations).
All disclaimers and warnings aside ... this Cmd feature can be disabled by adding this property to your build.properties file in .sencha/app/build.properties:
In Cmd v5 this particular optimization can be disabled while leaving others enabled like so: