20cv while a similar composition as m390 and 204p seems to be a bit better in not only my experience but in tests too. That can be due to the fact most manufacturers ht it to 60-62hrc like zt does. Even benchmades 20cv out cuts m390,which is generally only ht'ed to 58-61hrc on average from manufacturers.
While the composition is similar each of the three steels are made a bit different. The differences may be marginal but it seems to inch it out slightly. Would love to see an apples to apples test to be sure. All three are basically epic steel for 2018. Tests shown by Ankerson and Cedric Ada show more cuts with 20cv thus far. Even out cutting s90v which has been the crown for edge retention. Of course maxamet out cuts them all but has a few cons people don't prefer maxamet as much due to maintenance.
Tbo though fixed blades are often a lower Rockwell to provide more toughness to prevent breakage. Even then any of the three would be great,specially for bushcraft.