Employees can become managers. This class divide is so much less relevant today than it was due to startup culture. Funding is not that hard to come by.
If the divide is not great, there's no reason why collective representation of employees would "distort market forces." If c-suite can represent themselves, no reason why engineering guilds shouldn't have the power to determine the outcome of their companies. Especially if the class divide is not as great, as you say, then the employees would have similar incentives to that of management.