Original sentence: Other 'fat' benefices — even abbotships — were sometimes delegated to priests hired for a fraction of the benefice, while the family held the 'nominal' benefice.This practice encouraged the use of substitute priests of dubious quality: the lack of proper training (until the invention of seminaries) led to illiterate priests, a few even preaching heresy
Edited sentence: Other "fat" benefices — even abbotships — were sometimes delegated to priests hired for a fraction of the benefice, while the family held the "nominal" benefice.This practice encouraged the use of substitute priests of dubious quality; the lack of proper training (until the invention of seminaries) led to illiterate priests, a few even preaching heresy