In the 9.4 Software Release Notes doc there is the following statement:
This release of CA Spectrum supports the remote deployment of CA SystemEDGE only. As a result, remove your local CA SystemEDGE deployments, and deploy them remotely. The latest remote CA SystemEDGE deployments can now manage multiple vCenter servers.
Some customers have queried around this so to clarify the installation method does not matter you can do a manual install or remote deployment using any tool VAIM or ITCM.
What this statement is intending to say is that with this version of spectrum it is not supported anymore to run the vcenter aim on the vcenter server itself.
It needs to be on a agent remote from the vcenter server.