  Recent theoretical progress using multiscale asymptotic analysis has revealed
various possible regimes of stratified turbulence. Notably, buoyancy transport
can either be dominated by advection or diffusion, depending on the effective
P\'eclet number of the flow. Two types of asymptotic models have been proposed,
which yield measurably different predictions for the characteristic vertical
velocity and length scale of the turbulent eddies in both diffusive and
non-diffusive regimes. The first, termed a `single-scale model', is designed to
describe flow structures having large horizontal and small vertical scales,
while the second, termed a `multiscale model', additionally incorporates flow
features with small horizontal scales, and reduces to the single-scale model in
their absence. By comparing predicted vertical velocity scaling laws with
direct numerical simulation data, we show that the multiscale model correctly
captures the properties of strongly stratified turbulence within regions
dominated by small-scale isotropic motions, whose volume fraction decreases as
the stratification increases. Meanwhile its single-scale reduction accurately
describes the more orderly, layer-like, quiescent flow outside those regions.
