It does not conflict. Fiduciary duty for a for-profit organisation is not "profit at all costs", it's "you have to care about the company (care), you have to do

It does not conflict. Fiduciary duty for a for-profit organisation is not "profit at all costs", it's "you have to care about the company (care), you have to do good business (good faith) and you can't actively waste investors' and shareholders' money to intentionally lose out (loyalty)". If they are found colluding due to nepotism, both will get a very swift revocation of business licence and a huge prison term. Remember they are just one step of kinship away from presumed collusion.