Considering you will rarely get a Man of the Hour when you have a captain in command of a stack, it's preferable to use your family members as generals. A good method used by many is to use the young family members as generals and the elders as governors in the cities, for they normally have gained either influence or management skills.
With the new patch it's harder to bribe a stack but in case you don't have any choice, let a diplomat in the stack it will make the bribes rarer.