Handling Service Time Based on Pallet Count in Shipment

We are implementing a rate structure where the user requires different service times based on the number of pallets in a shipment. The equipment-to-max num of pallet is determined based on the ERU  configuration, and the following rules apply:

Business case:
A single equipment can hold up to 26 pallets.
If a shipment contains 26 pallets, the service time is 5 days. For shipments with 5 pallets, the transit time is 10 days.
Current Approach:
Since a direct solution for this requirement isn’t available, we tried the following workaround:
We created, individual rate service and rate record, based on the maximum number of pallets for a service time.