It wasn't correctly checking the current underlying health, which could
be zero in usages of `AccumulatingHealthProcessor`, for instance.
Closes#25046.
The end goal here is to be able to better coordinate deconfliction of
bindings at the subsection level rather than try to jam that logic into
individual rows somehow.
The flipside is that this is going to require a flow to update the
individual rows after the subsection's intervention, but that's what the
previous commit was for.