  The thick center vortex model reproduces important aspects of the potentials
between static quark sources as seen in lattice Yang-Mills calculations: Both
the intermediate distance behavior, governed by Casimir scaling, as well as the
long distance behavior, governed by N-ality, are obtained. However, when a
fixed vortex profile is used, these two distance regimes do not connect
naturally to each other. The transition in general violates concavity
constraints on the potential, especially for higher representations of the
gauge group. We demonstrate how this issue can be alleviated when the vortex
profile is allowed to fluctuate within this simple model.
