No! The server installer is able to install server and inventory.
Unsure of what needs to be installed to get inventory working.
The installers for Asset Trustee was separate until FileWave version 6 when inventory was now built it, but there was two isntallers
As of version 11 the two installers (one for server one for inventory) were combine into just one server Installer.
See the manual: 2.1. FileWave Server Installation