@Sharon_Hepburn @coastalcoffee
Shopify native has no concept of inventory pooling, or SKU grouping.
For the backend you must use an app to reconcile and sync inventory with such schemes.
Automation apps like usemechanic let you script custom business backend logic https://tasks.mechanic.dev/?q=sync
An alternative for the online sales channel is if the SKUs do not actually matter or affect price is to make a single product and use line item properties to inform you of what the customer is purchasing, requiring an advanced theme customization.