What’s your opinion? Should unit standards supersede Army standards?

A unit standard (Goal) should support, clarify or strengthen an Army standard. Generally you can incentivize reaching a unit standard but you wouldn't take adverse admin action against someone who fails to meet that standard. The Ranger Regiments standards are the one exception I can specifically remember as being an exception, those guys met the higher standard or were gone. (I was not a Ranger, just a support guy)
Like the old 18th Airborne Corps road march time standard was higher then the time standard in the FM for road marches. The Commander incentivized it by giving those who met the standard the rest of the day off and those who didn't had a standard duty day.
In all my years of service I never saw a Commander publish a unit standard or goal that "undermined" or did less then the Army standard.
I observed only one that tried to tie adverse admin actions to the standards and goals but in that case the standard and goal was rescinded and rewritten.
Command teams have access to the JAG and the IG who can provide input on "how to" achieve the commanders goal. Never ask those cats "Can I" ask them "How do I" and who's the Commander with Exception To Policy authority. Good staffing of these things help keep troops from getting hosed and Commanders from being embarrassed.

Ok In my day, the law was that the ARMY standard was the minimum, but that units could exceed that standard. Which is why 82nd,Rangers, SF, XVIIIABC standards almost always exceeded the Army's standards. Just passing isn't good enough when you are1st in the frying pan.

Army Standard is law. Add to but never take away from. But remember, Regulations are "guidance".