Skywatcher
Captain
The 18 ton payload is closer to the Y-9 than to the Y-7.However an-178's payload is meaningfully smaller than Y-9, let alone the Y-30 which is intended to have a 30 ton payload.
I think An-178 could have a role as a Y-7 replacement, however.
Of course, you could have a mixed fleet of AN-178s for the <20 ton payloads, and Y-30s for the larger tactical loads.
Though that's assuming that Beijing A-Star does follow through. There are Beijing A-Star companies that make all sorts of industrial components, so my guess is that BASTC is a subsidiary of whatever industrial conglomerate the A-Star name belongs to.