whats the difference between modality and

(traditional) planetary ruler?? I have this info but what difference does the title make?

Second Decan Cancer is most compatible with;

Based on (traditional) planetary ruler:

1st Decan Aries
1st Decan Taurus
2nd Decan Gemini
2nd Decan Cancer
3rd Decan Leo
3rd Decan Virgo
1st Decan Libra
1st Decan Scorpio
2nd Decan Sagittarius
2nd Decan Capricorn
3rd Decan Aquarius
3rd Decan Pisces

Based on Modality:

2nd Decan Aries
1st Decan Taurus
3rd Decan Gemini
2nd Decan Cancer
1st Decan Leo
3rd Decan Virgo
2nd Decan Libra
1st Decan Scorpio
3rd Decan Sagittarius
2nd Decan Capricorn
1st Decan Aquarius
3rd Decan Pisces

Really?