So it is possible that a building will get 'not enough workers' because while there are enough unemployed workers in the city, there are not enough unemployed educated workers to fill the educated slots.
Actually this can happen with high density commercial, industry and office too, but the very modest service requirements for low density commercial makes it more obvious. You may have noticed that if you provide low density commercial with a lot of services early in the game, it ran rapidly level up to lvl3 and then find itself unable to find educated workers and proceed to abandon.
