well, in the sample tested, avast is close to the bottom and Gdata is at the top. And yet Gdata still uses avast as one of its two scanners (as far as I know).
Certainly this outcome may happen, a conceivable result, in a lab environment anyway, whereas in real world circumstances, and especially 'in the wild', I think avast and Gdata outcomes would concur almost always 100% of the time.