There are many sets on Dragon Knight which has parts which clip with other parts of the set. It's mainly the shoulder guards clipping into Dragon Knight's arms, or into the chest armor of the same set.

Sets shouldn't have parts clipping with each other like that.

Sets with clipping parts:

1. Default set: Both shoulder guards clip into his arms
2. Armor of Sir Davion: Both bracers clip into his arms
3. Dragon's Ascension: The right shoulder guard clips with itself
4. Enchanted Plate of the Crimson Wyvern: The right shoulder guard clips into the chest armor
5. Fire Dragon of Doom: The shield clips into the shoulder guard, and the armor plate on his right leg clips through the cape
6. Legacy of the Eldwurm Crest: Right shoulder guard clip into his arm
7. The Blazing Superiority: Both shoulder guards clip into his arms
8. Uldorak's Hide: Both shoulder guards clip into his arms