Hello, we have some fringe computers that we want in inventory, but that are managed by different admins.  They want to continue to manage the server with their own patch tools and what not.

I've made a collection and put a test box in it, and I tried to disable software updates via a "client settings" policy, however they still are "managed" by configuration manager.  Is there a way to configure a windows client so it only does inventory and does not manage patches, therefore allowing the decentralized servers to be managed as they were?

TIA

a Group Policy always "wins" for Software Updates. So, two ways:

1) Those fringe computers deserve a GPO which smacks down ConfigMgr and points to their WSUS server.  GPO wins, always.

2) There are some things in ConfigMgr which, on a per-client basis, you have to use something called a "Local Policy Override", to tell the client, locally (not from a policy retrieved from the Management Point) to turn off a specific thing... like Software Update agent component.   Here's one person's example: http://www.hasmug.com/2014/12/30/disable-software-update-agent-on-sccm-2012-client/ 

(Sorta related): http://www.mnscug.org/blogs/sherry-kissinger/355-selectively-disable-software-distributions-and-application-deployments-on-clients

Since you said all you want is "inventory", you may want to deploy those ConfigItems (of course, that means that you'll have to break your own rule about "only inventory" and allow Compliance Settings and Baselines to be run).  You may want to also copy one of those configItems (probably the software Distribution Agent CI), and change it to do the Software Updates local policy override.