Bringing in Zach Brown may have been some theatrics to push Kiko to accept the long term deal Miami wanted (hey, they both play mike LB). The interesting thing to probably note is if Tannenbaum got the agreement in principle last night. If an agreement with Kiko hadn't been sorted out, you may well have seen a deal for multiple years for Zach Brown done today.
I may be wrong but I think Mike Tannenbaum was playing hardball and Zach Brown and his former agent were used as pawns in the process to lock in Kiko. The timing is not a coincidence. They knew ballpark what Zach Brown was seeking and went through the process of embarrassing him with a low-ball offer but Mike had the deal with Kiko already agreed.