I think it's a really good idea that you posted this and the following picture. Too many people have specifics like this for a character and don't have their references available.

Thank you.
The daggers are (in a way) Grimm's trademark. Just like the trinket dangling from his left ear.

Grimm's facial expressions, even the body layout may vary from artist to artist (and to be honest - this is what I love about comissioning artist - to get a view on my character through their eyes). But the small details that are Grimm's trademark stay the same through all Grimm interpretations. And that's what helps to recognize Grimm. This is why it is so important to have precise references for little details.