Hi Srihari,
I checked the method CL_MD_BS_SEARCH_PROVIDER_API~GET_SEARCH_METHODS where the search providers are collected and it seems that the search providers with search helps (i.e DB) are added first and then the other search methods. It might be a possibility to create an implicit enhancement at the end of this method to delete ES from the list and put it as the first search method.
Regards,
Kiran