Howdy! I have three in AWS, even with close to 1k APs and several hundred switches have we never come close to maxing out a single interface. We have several Radius servers, Cloudpath, Twillo, Hotspot services and DPSK running in and out of the cluster. For me, I've never even once thought about this or experienced this particular setup as an issue
Our VZ AWS cluster works similarly to our multi-interface VZ clusters we host in our data center.
I'll have to run some reports and see what the actual values are.