Confused about lactic vs acetic acid and sourness

From my research, acetic acid produces a more sour, vinegar-like flavour whereas lactic acid produces a more mildly sour, tangy flavor. However, I’ve been reading a lot of people baking with a liquid starter (which produces more lactic acid) and ended up with a sour loaf whereas people who used a stiff starter (which produces acetic acid) all claimed that it creates a loaf with milder/sweeter taste. Why is that?

Obviously the fermentation time of the actual dough is also a determining factor, but I assume these people all use different recipes but all claimed that stiff starter equals to a milder loaf and liquid starter equals to a more tangy loaf.

I’m asking because I want to make a very sour bread but I’m not sure if I should use a stiff starter or a liquid starter. And I don’t know if I should cultivate more acetic acid or lactic acid when I’m controlling the variables when baking in order to reach this goal.