Hi all... As far as I understand, the concept of "unitarity" is pretty close to that of perturbation; in that it tells you that your amplitudes are finite with energy scale (one solution the Higgs gave in e.g. the Vector Boson Scattering). However, since an EFT comes with a natural cut-off, why do people try to justify their validity using unitarity arguments? I mean, you are safe from an explosive amplitude by your EFT's scale. Thanks.