Of course, since many early pieces of Great Writing was originally declaimed aloud in public by design, would Herodotus, Aesop, and Homer be Great Writers or Great Entertainers?
Well considering there are only about 2-5 Great People an era and most civs have little need for amenity-increasing in the earliest ones, their progression could be a flip from some of the GWAMs (ie: writers go from 5 per era in the earliest ones to 2 and then only 1 in the latest), starting from 2 in the earliest and increasing in later eras.
Classical
1. A Roman gladiator, extending the reach of an Entertainment district (lighter version of the Colosseum with just the extension)
2. An Olympian, boosting Amenities from Entertainment District buildings
3. A performer from classical India or China, making Entertainment Districts provide Culture
Medieval
1. A bard, making a Great Work and providing +1 Amenities to the city it is created in (like how Joan of Arc creates a Relic despite being a General)
2. Someone that pioneered a style of dance (French or English?), increasing progress to a Golden Age
3. A jester, significantly reducing disloyalty in the city he/she is activated
Renaissance
1. An actor that reduces the threshold to a Dark Age (making you less likely to enter one)
2. A satirical performer that increases disloyalty when activated at the borders of another civ
3. A ballerina that provides a burst of culture based on a current city's amenities
Industrial
1. A circus ringleader (or P.T. Barnum if we're being specific) that allows some sort of circus building or project that boosts amenities
2. A circus act that boosts adjacency bonuses for ECs
3. A traveling show owner (wild-west?) that increases loyalty based on distance from the capital (farther cities get more loyalty)
4. A puppeteer that increases domestic tourism
Modern
1. A silent movie actor/tress that increases loyalty based on Great Works
2. A movie director that boosts GWAM points
3. An athlete that boosts amenities from stadiums and makes them provide tourism
4. A second athlete (there are lots of them) that immediately builds a stadium in an EC and provides an amenity
Atomic
1. A newspaper comic artist that allows amenities to spread to 5 cities instead of 4 (7 for the Aztecs, I guess)
2. A singer/dancer/performer (ala MJ or Cab Calloway) that makes Theater Districts provide an Amenity
3. An animated moviemaker that boosts progress to a Golden Age and creates a Great Work
4. An animal tamer that provides amenities from adjacent cattle/deer/whatever when activated
5. A radio entertainer that boosts Golden Age progress based on domestic tourism
Information
1. A comedian/enne that decreases disloyalty of all cities in a radius
2. A TV/soap opera actor that increases cultural pressure for tourism in the city he or she is activated in
3. A Broadway performer that gives progress to a Golden Age based on the number of Theater Districts
4. An athlete that boosts both domestic and foreign tourism when activated in a city with a stadium
5. A modern dancer that provides amenities when activated in a city based on its number of Great Works
