There is a technical term consequentialism, known better by the idiom the ends justify the means.
The concept holds that an action should be judged not by the inherent rightness or wrongness of the action, but rather by the outcome or consequences of the action.
Obviously, this idea is not without controversy, as it has been used to justify things that on the surface are outright wrong. A classic example is the atomic bombing of Japan- some historians argue that it saved millions of American and Japanese lives by ending the war before an all-out invasion could happen. These historians are using consequentialism in their arguments.
This may or may not work for your situation. For example, if you say, "It doesn't matter whether I learn complex analysis from Rudin or Palka, since the ends justify the means," some listeners will infer that one or both of those authors are inferior.