  Understanding the non-monotonic behavior in the temperature dependent
resistance, R(T), of strongly correlated two-dimensional (2D) carriers in clean
semiconductors has been a central issue in the studies of 2D metallic states
and metal-insulator-transitions. We have studied the transport of high mobility
2D holes in 20nm wide GaAs quantum wells (QWs) with varying short-range
disorder strength by changing the Al fraction x in the Al_xGa_{1-x}As barrier.
Via varying the short range interface roughness and alloy scattering, it is
observed that increasing x suppresses both the strength and characteristic
temperature scale of the 2D metallicity, pointing to the distinct role of
short-range versus long-range disorder in the 2D metallic transport in this
correlated 2D hole system with interaction parameter r_s~ 20.
