SPECTRA, Radar, Engines, even as Dassault claims that the skin is composites unlike Mirage 2000,
Thus the commonality might end up being several thousand Euros for nuts, bolts and ribits,
I think what they mean by commonlity maybe is that Rafale is just Mirage 2000 with two engines and canards.
After all Mirage III to Mirage 2000 to Mirage 4000 to Rafale is just modification of the base design Mirage III and nothing else.. Mirage III -- Mirage 2000 is Mirage III with better avionics,.. Mirage 4000 is twin engine Mirage 2000 with canards and more advance avionics. Rafale is remarketed Mirage 4000 with exaggerated SPECTRA
Everyone knows that Mirage 2000 is modified Mirage III
Food for thought
https://upload.wikimedia.org/wikipe...rage_2000B_top-view_silhouette_comparison.png