Automatic Shipment Creation

I have a requirement for Automatic Shipment Creation. While creating the variant for "Data & options" I am able to enter a single Route. Business wants Item for 2 Routes X and Y should be in one truck. I have created 2 different variant for Route X and Route Y. My assumption is that batch job will create 2 different shipment for Route X and Route Y and during shipment execution need to enter same Truck number manually. Is my understanding correct? Or else how to handle this?