I will suggest, you take one of the pChat servers from the pChat pool, install SE FE on that server and then collocate pChat server on that server, move CMS to this server then you can remove the 3 additional servers.
If your business needs DR feature (on FE and pChat), you can install an additional SE FE on one of the other servers and collocate pChat on that one as well.
Same featureset, almost same level of security (DR is not HA) and your business will save a server license.
Kenneth ML || Please remember, if you see a post that helped you please click Vote on the left side of the response, and if it answered your question please click Mark As Answer.