I guess it depends on how we meter the scene we want to capture but your example does not convince me that the Fomapan 400 is even close to an Iso 400 film. Looks much closer to an Iso 200
There is no definition in all the blacks, could of course be intentional that you have printed the shades down to retain highlights.
There's still only one film that is remotely close to Iso400 and that is the TMY400, HP5+ is closer to 200 in real life.
I just used the sunny 16 formula in exposing the shot. I think the Arista film is ASA 400 because the deep shadow areas has detail. Is that how one rates film?