Medical workers: 6 amenities (instead of 10 for an entertainer) and 5% pop growth, or in other words 55.5 years to break even. Pop growth is additive so best to look at it in terms of absolute growth instead of percentage based. Entertainer during that same time gives 2 unity before any bonuses. I'm going to guess that the entertainer is the superior pick in this case.
Clerk: 2 trade and 2 amenities for a worker class. Amenity positive. Assuming no benefits it's either producing 2 energy or 1 energy and .5 consumer goods. How good is that? Technicians produce 4 energy and have more potential for bonuses, but clerks are really good for concentrated real estate. Technician jobs are limited by districts, with one or two extra jobs with the energy building. For the living conditions that require .25 or less you're making a net positive consumer goods. A city district provides 5 housing, plus one building slot for clerks gives 6 jobs for a net 6 energy, a bit of consumer goods and amenities, and -1 housing (but housing can be increased with tech). Compared to the technician district giving 8 energy.
Is that good? Kind of a wash really. Terrible option if you have high costs per worker, good if they're cheap. Getting a few merchants with the upgraded clerk building helps a lot. They're definitely paying for themselves, and having more ruler class pops helps a lot for increasing stability. Main benefit I'd think is how reliable that build can be. Generator districts are limited by planet. Some will have a few, some a lot. But every planet can build city districts and clerk buildings. Build the society right and they're highly beneficial.
