  The hierarchical model of structure formation is a key prediction of the
Lambda cold dark matter model, which can be tested by studying the large-scale
environment and the substructure content of massive galaxy clusters. We present
here a detailed analysis of the clusters RXCJ0225.9-4154, RXCJ0528.9-3927, and
RXCJ2308.3-0211, as part of a sample of massive X-ray luminous clusters located
at intermediate redshifts. We used a multiwavelength analysis, combining WFI
photometric observations, VIMOS spectroscopy, and the X-ray surface brightness
maps. We investigated the optical morphology of the clusters, we looked for
significant counterparts in the residual X-ray emission, and we ran several
tests to assess their dynamical state. We correlated the results to define
various substructure features, to study their properties, and to quantify their
influence on simple dynamical mass estimators. RXCJ0225 has a bimodal core, and
two massive galaxy groups are located in its immediate surroundings; they are
aligned in an elongated structure that is also detected in X-rays. RXCJ0528 is
located in a poor environment; an X-ray centroid shift and the presence of two
central BCGs provide mild evidence for a recent and active dynamical history.
RXCJ2308 has complex central dynamics, and it is found at the core of a
superstes-cluster. The complexity of the cluster's central dynamics reflects
the richness of its large-scale environment: RXCJ0225 and RXCJ2308 present a
mass fraction in substructures larger than the typical 0.05-0.15, whereas the
isolated cluster RXCJ0528 does not have any major substructures within its
virial radius. The largest substructures are found in the cluster outskirts.
The optical morphology of the clusters correlates with the orientation of their
BCG, and with the position of the main axes of accretion.
