Behaviour of [Na/Fe] and [Al/Fe] as a function of [Fe/H] for the Sgr spectroscopic targets of this study (same symbols as in Fig. 1), in comparison with the abundances of MW GCs analysed by Mucciarelli et al. (2023b, orange star symbols) and with the MW field stars from the SAGA database (Suda et al. 2008, grey circles). The empty red squares are the metal-rich Sgr targets belonging to the blue side of Sgr RGB (see Section 4). The typical errorbar of the abundance ratios measured for Sgr stars is shown in the bottom left corner.