They understand revision control because it is built into Word... But my previous lawyer would send the document to me and to my CFO, each of us would make changes and I would talk to the lawyer on the phone. Soon there were three versions of the document, so there were threads going back and forth around "which is the latest document".

As for EchoSign, they authenticate that the person who signed the document must have at one point clicked through a link which went to their e-mail address. This is much better than the authentication of written signatures, i.e. that someone could scribble something on a piece of paper in the same way that you did it.