Queue assignment rules

Summary:

Hi Team,

We have requirement to define the queue assignment rules based on two different rule set.

1. Based on category & Legal Employer of the primary point of contact

2. Based on support mailbox & Legal Employer of the primary point of contact

We need to define the priority also i.e. 1st mailbox should take preference then category rule. 

I assume this is possible through scoring functionality, but I am not able to achieve this. 

Does anybody has configured this before, need some inputs?

Thanks