Cortex-R4: Need a explanation for dual-issue restriction

Hello,

The following table is extracted from the Cortex-R4 whitepaper:

Could someone help me to explain that question:

My concern is that Cortex-R4 can take MOV as first instruction, ADD as second instruction to a dual-issue pair in C category means that it is not limited by the data-path pipelines resource.

So, Cortex-R4 should be able to extend the A category to a version with second instruction including a additional MOV instruction.

Why cannot use ADD(Some data processing instruction) as first instruction and MOV as second instruction?

Thanks