Eric, Catcher A understands the game better. her catching coach drills her on scenarios from what I understand. She calls the pitch and sets up to where she calls it. She barks out the number of outs to the defense, etc. Very hard worker...vocal..but humble. Catcher B plays hard...but can be lazy with technique. She tries to get by with athleticism. Both really play hard. From my perspective Catcher A seems to know more.
Catcher A is my starter until Catcher B reaches A's level of game knowledge and leadership.