The consultant should retain sharing rules during the data import because they control the access and visibility of records based on criteria such as record ownership, role hierarchy, or field values. Disabling sharing rules may cause data security or privacy issues. Workflow rules and role hierarchy are configurations that can be disabled during the data import to improve performance and avoid errors or conflicts. References:

https://help.salesforce.com/s/articleView?id=sf.data_loader_disable_triggers_workflow.htm &type=5

https://help.salesforce.com/s/articleView?id=sf.data_loader_sharing_rules.htm &type=5