1
... for me, is that (basically) all hitters choose whether to 'get the pitcher early in the count' or whether to work the count.
Guys who accept deep counts (or, those who miss their first swings a lot) are going to have higher K and higher BB to go along with them.
There's nothing fundamentally better about 50:30 strikeouts and walks vs 100:50. The second guy is just starting off with a 1-1 count.