How can I negatively colocate resources in a Pacemaker cluster so that one doesn't depend on another's placement?

Issue

• I want to make sure that no two resources in a set of resources ever run on the same node. Additionally, I don't want to require that any one resource be placed before any other resource. How can I achieve this?
• I have a set of three resources (rsc_A, rsc_B, rsc_C), and they should always run on separate nodes. If only two nodes are available, then one of the resources should stop and the other two should remain running in place. I configured the resources into a colocation constraint set with score=-INFINITY as shown below:

    set rsc_a rsc_b rsc_c setoptions score=-INFINITY

But when I take down node1 where rsc_a is running, rsc_c stops on node3 and rsc_a starts in its place.

Performing requested modifications
 + Taking node node1 offline
...
Transition Summary:
 * Start      rsc_a              ( node3 )  
 * Stop       rsc_c              ( node3 )   due to node availability