A major path helping agriculture achieve the dual challenges of production and environmental preservation, consists of transitioning from the current, external input-based, conventional farming systems to a biodiversity-based agricultural system that rely more on ecosystem services. One lever of this transition consists of diversifying agri-food systems using practices such as rotation extension, intercropping (IC), multiple cropping or multi-services cover crops (MSCC) implementation. Here, we investigated to what extent the combination of diversification practices could contribute to the enhancement of the sustainability of current conventional cropping systems through an ex ante evaluation. We compared the sustainability performances of five diversified (DIV) cropping systems from five major arable crop production regions of France to their local less diversified reference (REF) systems by calculating various criteria and implementing a multi-criteria decision aid model. 76 criteria assessing the three dimensions of sustainability were calculated (10, 17 and 49 criteria for the economic, social and environmental dimensions respectively). Our analysis showed that the combination of diversification practices could improve the environmental performances while maintaining a priori economic and social performances at satisfactory levels according to the local expert working group. The DIV systems always had lower greenhouse gas (GHG) emissions compared to their REF systems and often improved air and water quality and above- and belowground biodiversity. However, diversification may also cause drawbacks for some indicators, as negative impacts were observed from, gross margin, NO3 lixiviation, NH3 volatilization or pesticide use, in some cases. Our analysis also suggested that the effect of a combination of diversification practices on an indicator can be either positive or negative according to the pedo-climatic context, the level of performance of the reference and compromises in the management of diversification practices in response to local objectives of performance.