A palisade without a claim is unprotected, and doesn't need siege engines to break, no matter the age. This was added several months ago to requests for easier means to remove unsupported claims from the world.
Best suggestion: Build a village charter. You can extend it downwards as long as the banner is under any existing part of the village claim. This will eliminate the need for multiple personal claims to protect various holdings in a main. (Note that it can only be extended down, and only one level at a time, so to cover level 5, you need to cover level 1-4, too.)
edit: relevant patch notes:
viewtopic.php?f=39&t=65336&hilit=palisade+bash#p8277892nd edit: I nothiced that change never made it into the wiki. It's fixed now.
Opinions expressed in this statement are the authors alone and in no way reflect on the game development values of the actual developers.