  We explore the scaling between the size of star-forming clumps and rotational
support in massively star-forming galactic disks. The analysis relies on
simulations of a clumpy galaxy at $z=2$ and the observed DYNAMO sample of rare
clumpy analogs at $z\approx0.1$ to test a predictive clump size scaling
proposed by \citet{Fisher2017ApJ...839L...5F} in the context of the Violent
Disk Instability (VDI) theory. We here determine the clump sizes using a
recently presented 2-point estimator, which is robust against resolution/noise
effects, hierarchical clump substructure, clump-clump overlap and other
galactic substructure. After verifying Fisher's clump scaling relation for the
DYNAMO observations, we explore whether this relation remains characteristic of
the VDI theory, even if realistic physical processes, such as local asymetries
and stellar feedback, are included in the model. To this end, we rely on
hydrodynamic zoom-simulations of a Milky Way-mass galaxy with four different
feedback prescriptions. We find that, during its marginally stable epoch at
$z=2$, this mock galaxy falls on the clump scaling relation, although its
position on this relation depends on the feedback model. This finding implies
that Toomre-like stability considerations approximately apply to large
($\sim\rm kpc$) instabilities in marginally stable turbulent disks,
irrespective of the feedback model, but also emphasizes that the global clump
distribution of a turbulent disk depends strongly on feedback.
