When the entities are separate and independent, the commonality of their ownership doesn't matter in effecting changes in the service of the employees therein, except for the quick approval of any decision in this regard.
Clarifications needed for employee transfer
However, firstly, certain clarifications are required from the poster if the change intended is limited to that of transfer of services only: Whether only those employees of Lead Mazza currently deputed to serve in Dreambig are to be transferred to the rolls of the latter or all of the former? Whether it is possible to effect such a transfer with continuity of service and attendant benefits to the employees bilaterally between both the entities, or do the employees concerned have to be consulted either individually or collectively through their Union, if any?