Question about the IKO topology

Hi,

Are we correct to assume that the IKO topology only allows for the use of one 'data' node type, and one 'compute' node type? So if we want to use several different iris based compute nodes (or data nodes) we have to apply several yaml files? So the following topology config is not possible:

topology:
    data:
        image: dvza.healthexchange.nl/mmres:0.1
    data:
        image: dvza.healthexchange.nl/mmauth:0.1
    data:
        image: dvza.healthexchange.nl/somethingelsethatisbasedonirisimage:0.1

Thanks in advance.