Close but not quite correct. Campy (ISO) tapers and Shimano (JIS) tapers have the same 4° included angle but the ISO taper starts out with a slightly smaller dimension across the flats at the small end.

So, a Campy crank usually won't go adequately far up a JIS taper and a Shimano crank will usually go too far up an ISO taper. I say "usually" because the differences are small and tolerances sometimes let the cranks interchange adequately.

Try your Campy crank and see if it goes on the Shimano spindle far enough to be secure and if the chain line is good. It may work but there is no guarantee.