  Observations of clusters suffer from issues such as completeness, projection
effects, resolving individual stars and extinction. As such, how accurate are
measurements and conclusions are likely to be? Here, we take cluster
simulations (Westerlund2- and Orion- type), synthetically observe them to
obtain luminosities, accounting for extinction and the inherent limits of Gaia,
then place them within the real Gaia DR3 catalogue. We then attempt to
rediscover the clusters at distances of between 500pc and 4300pc. We show the
spatial and kinematic criteria which are best able to pick out the simulated
clusters, maximising completeness and minimising contamination. We then compare
the properties of the 'observed' clusters with the original simulations. We
looked at the degree of clustering, the identification of clusters and
subclusters within the datasets, and whether the clusters are expanding or
contracting. Even with a high level of incompleteness (e.g. $<2\%$ stellar
members identified), similar qualitative conclusions tend to be reached
compared to the original dataset, but most quantitative conclusions are likely
to be inaccurate. Accurate determination of the number, stellar membership and
kinematic properties of subclusters, are the most problematic to correctly
determine, particularly at larger distances due to the disappearance of cluster
substructure as the data become more incomplete, but also at smaller distances
where the misidentification of asterisms as true structure can be problematic.
Unsurprisingly, we tend to obtain better quantitative agreement of properties
for our more massive Westerlund2-type cluster. We also make optical style
images of the clusters over our range of distances.
