When an envelope doesn't have any tags for a signer, DocuSign allows that signer to add a signature tag and adjust its size.  The Sign a Document flow is an example of this.  If an envelope has a signature tag, the signature tag usually starts out at the largest size and the sender has the option to decrease the size.  If you are receiving a document with a signature size that doesn't look quite right, it makes me wonder whether the recipient has any tags.  If you create a copy of (but don't send) the envelope, do you see any tags in it?  One possibility could be that the envelope sent without any tags, the signer added one, and the signer sized it incorrectly.