I think those SHFs should not spawn in missions, they are so much more deadly compared to the VHF swarms you get from factions that dont have SHFs
Rogues are a great example of that issue, since a lot of newbies that just simply start on penn seem to get absolutely destroyed by them spawning in even lower paying missions
a lot of factions dont have SHFs with freighter shields and massive armor, why should a few have them and make them so much more difficult?
having them as step between the normal fighter swarms and gunboats would also be nice, for the factions that have no SHF on their own theres still the spatial, IMG npcs use those for example