The Koathites were not better than the other sons, they just had a different set of duties to perform. The same holds true today, spiritually speaking the Koathites are the pastors and teachers. Pastors are not elevated above any of the other members of the body of Christ. Pastors just have a different set of responsibilities and duties to perform. The Gershonites and the Meari-ites also have their own set of responsibilities and duties to perform, an in like manner, so do all of the other members of the body of Christ. Or to be more specific to a local assembly, all of the members of any given congregation all have their own specific set of duties to perform to keep the work moving forward.