Definitely. Firewalls and most other common measures focus on attack patterns – viewing the target system from the inside out. The goal is defending against attacks that are actually occurring. For this reasons, these systems only engage once an attack is already on the way.
In comparison to this, vulnerability management views the IT-infrastructure from the outside in – just like a potential attacker. The goal here is to eliminate attack surfaces in order to stop any attacks from happening in the first place.
High grade firewall systems can occasionally detect vulnerabilities, however contrary to vulnerability management they will not propose any measures to eliminate them. Additionally, firewalls, IDS- or IPS-systems can only detect weaknesses if the system they are running on allows them to do so in the first place, and even then they will be restricted to a range of traffic correlating to the respective system security.
Traffic which does not pass through the security system will not be analyzed either. If a Greenbone solution is implemented in the network, every component that can be reached via an IP-connection can be probed for weaknesses, no matter the type of device. This, for example, also includes industrial components, robots and production plants.
A combination of firewalls etc. and vulnerability management is certainly the best solution. With the insight vulnerability management provides, the use of other systems can be focused on important hot spots.