Nope you were being helped... the "stamps" analogy retort was an attempt to explain to a more experienced member that he was complicating things for you needlessly.

The "Y" cable arrangement is the simplest way to go about your setup.

BTW: Setting up mechanical differentials using your "Y" cable is trivially easy too. All you need to do is have the TX at stick center, then position each of the aileron servo control horn arms canted forward by an equal amount on each side. The more forward the horn position, the more differential you get.... nothing to it...

But that's for more advanced trimming and tuning, and may be beyond the scope of a beginner's section.