Every machine's design/head design/bias circuitry is unique. Taking a look at this Technics reference - one data point out of many out there - they define the Bias & EQ settings for a Maxell UD tape = a Maxell LN (low noise).
Food for thought !
The compact cassette sector tried to alleviate this 'settings' confusion/inconsistency problem with better standardization - but as better as it seemed to get on the marketing surface, the fact remained that tape stock varied - mechanicals varied - bias controls varied along with bias electronics... etc etc
Ultimately, three headed machines with +/- % bias (dial) controls and multi-staged EQ selectors made the most sense on the higher end products. In this way, the user could fine tune to their subjective ear and compensate for all the prior listed variances.