[Mobhack]

SEAD aircraft carry ARM - it is the whole point of the class, otherwise players get confused when ARM-equipped ordinary strike planes wander off from the intended target point and offload on a ZSU-23-4. No SPMBT SEAD planes have zero ARMs (until all expended, when they operate as normal strike planes of course). And having a separate class allows the AI to chose these types planes for SEAD tasks when picking forces as well.

As to why that particular missile is on that particular plane - you would need to ask the designer(s) of the USA OOBs over the last 5-6 years or so.

Cheers
Andy