No real logical reason Jay.
It is just that the Dogfight feels to me like a gruntier reel - I think it is that incredibly robust, one piece handle compared to the relatively intricate Shimano folding handle design.
I know you are being tongue-in-cheek, but an upgraded Dogfight drag is as good as a Stella out of the box
.
Somehow I always load my Dogfight with PE10 and 18000 with PE8, but as I said, it is probably no more than perception that makes me do that.