You're not really in "violent agreement" when you're just agreeing with him from the outset.
https://wiki.c2.com/?ViolentAgreement
I definitely think of the term pretty much exclusively in the sense of (a) here, i.e. extreme, vehement agreement:
http://listserv.linguistlist.org/pipermail/ads-l/2007-Septem...
You're not really in "violent agreement" when you're just agreeing with him from the outset.
https://wiki.c2.com/?ViolentAgreement