Hi @ArloS ,
the Deployment Models are: Evaluation, Small, Medium and Large (please take a look at Performance and Scalability Guide).
The Dispersed Network Deployment is part of the Large Deployment.
In the past we have: Standalone (a deployment that has a single ISE Node) or Distributed (a deployment that has more than one ISE Node) Deployments (for ex.: ISE Installation Guide 2.4 - search for Standalone and Distributed ISE Deployments)
In other words ... take a look at Large Deployment info for better understand of Dispersed Network Deployment.
Hope this helps !!!