Granny Smith thinks her grandsons would be a perfect trio.
Big Mac is heart and Applejack is the stabilizer, on the other hand Granny Smith thinks once she gets older Applebloom might be a bit of the brains of the three.
The first is the morale as he’s the one always checking for everybody’s wellbeing, the second is the tradition and the one who keeps the apples on track regarding their values and the third will be the improver with the sidethinking to kept the apples from being complacient.