Cluster pickin in Odoo should be the right process. The carts are not locations there, but Odoo uses package functionality ("Resuseable" type).  You label these cart with a barcode, adn assign each of them to a sales order. 

Read here:

https://www.odoo.com/documentation/17.0/applications/inventory_and_mrp/inventory/warehouses_storage/advanced_operations_warehouse/cluster_picking.html