In this article we derive a measure of quantumness in quantum multi-parameter
estimation problems. We can show that the ratio between the mean Uhlmann
Curvature and the Fisher Information provides a figure of merit which estimates
the amount of incompatibility arising from the quantum nature of the underlying
physical system. This ratio accounts for the discrepancy between the attainable
precision in the simultaneous estimation of multiple parameters and the
precision predicted by the Cram\'er-Rao bound. As a testbed for this concept,
we consider a quantum many-body system in thermal equilibrium, and explore the
quantum compatibility of the model across its phase diagram.