Take a look at Pega 7.4. The one place where Struts is used in Pega is in the System Management Application (SMA) where requestors, agents, etc. were managed in older versions. In 7.4, the functionality that used to be in SMA has been migrated to landing pages in Designer Studio. So, you no longer need to deploy SMA.
I believe that there are one or two rarely used features from the SMA that didn't make it over to the landing pages, but those functions are also there in the Pega REST API. So, worst case, you can access them manually through a service call if absolutely needed.