To keep a WLAN environment secure, it’s important to stay on top of new wireless vulnerabilities which can be achieved by regularly performing a vulnerability assessment on your wireless network. This provides leverage over the enterprise that enables you to identify and close any security holes before a hacker can sneak into your network. Your concern about the difficulty containing an attack in a large footprint is a valid point, but remember that several smaller footprints will pose greater risks as they require series of independent processes and controls.
As I clearly suggested earlier, it will be counterproductive in a situation you are racing against time in trying to mitigate an attack or attacks on your network. For example, with a large footprint vulnerability assessment, you’re figuring out what your company and business network looks like to the outside world on the Internet. Are these footprints actual representation of my business or has someone hijacked my reputation? You can manage that large footprint by simple uniform security policy with limited protocols and controls.
In a several small footprint, to make that assessment could pose potential threats that make the enterprise vulnerable to attacks and it is time consuming and drains resources. Managing several footprints could put you in a situation where you are dealing with so many different footprints which could actually sometimes make it impossible to remediate an attack.
Choudhur, S., (2012) 5 Steps for assessing your wireless network security Retrieved March 22, 2018 from https://blogs.cisco.com/smallbusiness/5-steps-for-assessing-your-wireless-network-security