I'm ok with it being default behavior. It's actually correct that in a melee range, melee weapon is prioritized over gunbutt, because if you have a pistol and a sword, then the sword should be used.
However, I still think that if I did indicate priority, then gunbutt should be prioritized over melee weapon. Think about it. If you have a ranged weapon and a melee weapon, what would priority do?
It's certainly not for a ranged attack, since a melee weapon can't attack at range. If you have only one ranged weapon, then priority obviously won't change anything.
So it's simply logic that the player wanted to set up priority for a melee attack. This isn't a maybe; in this case we can say with 100% certainty that this is what the player wanted. That the player wanted to prioritze the melee attack of one hand over the melee attack of the other hand.
So yeah, I can see the reason why it's melee first and gunbutt second by default. But we're talking about the "manual override of default behavior" here, which is what the preference indication does. Or should do?