  Expressing attack-defence trees in a multi-agent setting allows for studying
a new aspect of security scenarios, namely how the number of agents and their
task assignment impact the performance, e.g. attack time, of strategies
executed by opposing coalitions. Optimal scheduling of agents' actions, a
non-trivial problem, is thus vital. We discuss associated caveats and propose
an algorithm that synthesises such an assignment, targeting minimal attack time
and using minimal number of agents for a given attack-defence tree.
