Jimlock
Adventurer
Sundering something doesn't necessarily mean hacking it till it breaks. That shield, for example, could easily be made 'useless' by severing the straps that hold it to the forearms. Or by punching your dirk into one of the seams that hold the boards together, then leveraging laterally. Rolling that 6 on the damage roll (max damage) could easily be interpreted as "you get a good grip on his left forearm with your free hand, then quickly slice his shield straps. The targe is now practically useless...", or "you tackle him and PUNCH your dirk right through his shield. Two or three sideways heaves later, part of the shield's wood splinters off. Your opponent shakes the ruined targe off his arm in disgust and attacks you...".
Similarly, you CAN lock a longsword with a dagger, at least if you have any kind of prongs on it. Being good at sundering means you find and catch the one spot along the length of the enemy's blade where it is weakest, and don't run a risk of ruining your dagger in attempting to break the longsword. Or maybe you just break the longsword's hilt when you catch his counterstroke really in close. Or something.
This seems to be a point I come up with a lot in WB's threads: if you imagine a scene based upon real world experience, or a movie you've seen, or whatever, and then apply the rules to that individual image in your head, you'll easily get a disconnect. However, if you take the rules as your baseline and imagine from there, things get much easier much of the time. Daggers CAN sunder longswords, although it ain't easy. Given that piece of axiomatic knowledge, let your imagination run wild on HOW it works.
I owe you an XP. Very good point.