I got crushed by 1st inning and division showdowns, but just did NL Stage 2 and kicked [censored]. It was super close at times but managed to pull through, and despite choking the last two or three missions at the end I managed to score 7 runs hella quick with my gold heavy lineup. Whatever one you choose, Google the showdown and find a guide on Reddit or elsewhere that tells you about the missions if you don't consider that cheating. Certain showdowns you wanna stack lefties or righties.