You seem to be suggesting that workers should form unions, such that, when the working class develops enough power, it should use the power to press the state to force workers to form unions.
An essential issue seems to be of circularity.
A further quite severe doubt for me is the meaningfulness of organization among workers who have not sought organization. Unions require active participation from members who believe that being organized is valuable and who conceive of themselves as agents of their own liberation.