Good idea, so long as it does not override the customer assigned sales rep. And this should be an optional setting.
When implementing this, also consider how this feature request plays with it:
Yes, for new customers on shopify - the sales rep from SHOPIFY flows through to the SALES part but not the inventory_customer level. So a "designer" in shopify is a "designer" in sales but may well be a "Wholesaler" in inventory_customer depending on the order of the contact in reference book. This does not make sense.