From your pragmatic standpoint, knowing someone's limitations up-front is valuable to avoid putting them in situations where they will fail to do something beneficial that is either expected of them or they have historically done under different circumstances.

For example one problem I have noted for a long time is that the most vocal and public defenders of people on the right are liberals (eg. Peterson, Tim Pool, Joe Rogan), and a time will inevitably come when the right goes someplace these liberals can't follow; at which point they'll stop defending the right at best and at worst turn coat and attack.