I believe the mare is the most important due to the fact that most foals will adapt to their dam's attitude since they're with them every day. The sire does have contributions but you should look the mare to see if she should even be bred in the first place. With some mares, you'll get lucky the stallion adds his good traits verses some bad mares.
Proud Partner Owner of Me Too Radical, Top 10 PQHA Quality Improvement Program Futurity. Sire of AQHA, NSBA, and NRHA champions. Sweet, gentle, excellent mover, excellent temperment, and so much more. Standing in Indiana.