ClusterX a_123(something) b_234(something new)    c_897(some different thing)
ClusterX     -            b_675(some_other_thing)     -                      
ClusterY b_6998(some_other_thing, thats new) c_111(some other different thing)        
ClusterY     -                               c_877797(something different inside here)
ClusterZ 2_1789(another new one) a_1234(something interesting)                    
ClusterZ 2_12243(a new one)      a_123467(something - else thats is - interesting)