AnyLogic: Move two agents simultaneously into a pallet rack

I want to model a double-deep pallet rack in AnyLogic that contains two types of agents: small boxes and big boxes (2 different agent types that extend the gereral agent "Box"). Here I have a question regarding the movement into and from the pallet rack:

I need my vehicle/moving resource to be able to move either 1 big or 2 small boxes (or only 1 small box if needed) at the same time from the spawn into the pallet rack and some time later from there to the despawn. My problem is that I don't know how to tell the resource to pick up 2 agents simultaneously, if it`s possible. Is there a way to solve this problem?

Thanks a lot in advance.

You should be able to use the batch and unbatch blocks to simulate combining the two small boxes into 1 temporary agent, moving them and then unbatching them. See example below