H I properties recovered by applying our modelling technique on mock H I observations of idealised, axisymmetric systems. Left panel: an idealised disc with flat profiles of v_φ, σ, n₀ and h_s. The solid lines show the profiles used as input for the creation of the mock datacube. The system has two components, one with high-density and low σ (blue line), and one with low-density and high σ (red line). The points with error bars show the system parameters as recovered by our modelling technique. Middle panel: the same system of the left panel, but with the additional presence of a slow-rotating and inflowing extra-planar H I (see text). Our modelling technique overpredicts the scale height of the disc. Right panel: as in the middle panel, but now our modelling technique takes into account the presence of the extra-planar H I and recovers the input disc scale height.