In our current evaluation subscription, what we have is:
1) one host ( as a VMWare guest ) running RHEL6 with EWS 2.1
2) another host ( also a VMWare guest ) running RHEL6 with JBoss EAP 6.2
In both instances, EWS and JBoss EAP 6.2 were installed via rpm / yum. There will be more than one host for both  and  ( e.g. multi mod_cluster + multi JBoss EAP ). That is the intention for the production environment.
For our non-PROD environment, however, due to capacity limitations ( e.g. there is not enough capacity to have more than X number of new guests OS in the VMWare farm in the non-production environment ), we were thinking that for non-PROD, we would have both EWS 2.1 and EAP 6.2 on the same host.
However, I have just read the following, where it recommends to NOT install both EWS and EAP on the same host using the same installation method:
That is, either EWS via ZIP and EAP via rpm/yum .. or the other way around.
We are only using EWS for the purpose of software load balancing with JBoss EAP in the backend. Apart from that, EWS will have PHP apps as well. Since our EWS installation will not use Java at all, can we assume that we can still then install EWS and EAP via rpm/yum on the same host ? Simply because installing via rpm/yum takes the guesswork out of installing the dependencies.