Reddy,
The remote execution will work, but this will have a variety of downsides.
Depending on EXACTLY how you have set up security, one approach is to FTP to connect to each of the non-Automic servers and have the script initiated via an advanced FTP command (both your OS security and your FTP server and client software must be configured to allow this).
NOTE: If you are using one of the above approaches to initiate load on remote servers, you have to determine how you will pass back the status/result of script BACK to Automic. "Fire and forget" is rarely a viable option.
Many (most in my experience) organizations do NOT allow FTP/RSH/ Rexec/PSexec to be invoked in this way: the security and audit trails provided by Automic and other similar tools are why organizations use these tools to manage load on thousands or tens of thousands of servers.
Another option, depending on your environment and applicaitons, could be to use an Automic Web Service Agent to initiate contact with and submit load on the remote servers
In re-reading your original request: A single AE (Automation Engine) on Linux or Windows or Solaris or ... can control load on thousands of Agent servers running different OS's.
One reason for using two servers is for high availability -- The AE software on the two servers can be set up as an active-active pair or active-passive. The Agents on the actual AE servers should NOT be used for much actual executing job load--too much opportunity for interference between the Automic internal demands and the end-application demands