We expand our study on the full-Heusler compounds [I. Galanakis \textit{et
al.}, Appl. Phys. Lett. \textbf{89}, 042502 (2006)] to cover also the case of
doping and disorder in the case of Co2MnAl and Co2MnGa half-metallic
Heusler alloys. These alloys present a region of very small minority density of
states instead of a real gap. Electronic structure calculations reveal that
doping with Fe and Cr in the case of Co2MnAl retains the half-metallicity
contrary to the Co2MnGa compound. Cr impurities present an unusual behavior
and the spin moment of the Cr impurity scales almost linearly with the
concentration of Cr atoms contrary to the Co2MnZ (Z= Si, Ge, Sn) where it
was almost constant. Half-metallicity is no more preserved for both Co2MnAl
and Co2MnGa alloys when disorder occurs and there is either excess of Mn or
sp atoms