High ACT and Low SAT Subject tests

How much do subject tests (that are required by the school) weigh into the admission process?
Does the ACT score matter much more? as in enough to outweigh poor/average subject test scores?

It will depend by school (and possibly panel looking at the record). That’s why it’s called an holistic review.

For competitive schools, the ACT/SAT1 scores percentiles are usually higher than the SAT2 score percentile.