  We investigate a set of topological arrangements of individual ferromagnetic
islands in ideal and disordered artificial spin ice (ASI) arrays in order to
evaluate how aspects of their field-driven reversal are affected by the model
used. The set contains the pinwheel and square ice tilings, and thus a range of
magnetic ordering and reversal properties are tested. We find that a simple
point dipole model performs relatively well for square ice, but it does not
replicate the properties observed in recent experiments with pinwheel ice.
Parameterization of the reversal barrier in a Stoner Wohlfarth model improves
upon this, but fails to capture aspects of the physics of ferromagnetic
coupling observed in pinwheel structures which have been attributed to the
non-Ising nature of the islands. In particular, spin canting is found to be
important in pinwheel arrays, but not in square arrays, due to their different
symmetries. Our findings will improve the modelling of ASI structures for
fundamental research and in applications which are reliant upon the ability to
obtain and switch through known states using an externally applied field.
