  Working with proton and pion valence distribution functions (DFs) determined
consistently at the same, unique hadron scale and exploiting the possibility
that there is an effective charge which defines an evolution scheme for DFs
that is all-orders exact, we obtain a unified body of predictions for all
proton and pion DFs - valence, glue, and four-flavour-separated sea. Whilst the
hadron light-front momentum fractions carried by identifiable parton classes
are the same for the proton and pion at any scale, the pointwise behaviour of
the DFs is strongly hadron-dependent. All calculated distributions comply with
quantum chromodynamics constraints on low- and high-$x$ scaling behaviour and,
owing to emergent hadron mass, pion DFs are the most dilated. These results aid
in elucidating the sources of similarities and differences between proton and
pion structure.
