The same candidate file can be harmless to one downstream job and fatal to another. That is why this product refuses to emit a single global verdict and asks you to describe consumers instead.
A consumer policy is four decisions
For each consumer you record the columns it requires, the observed types it tolerates for those columns, whether it binds by position or by name, and whether it tolerates columns it did not expect. Those four decisions are enough to turn a list of structural differences into a per-consumer answer.
Required columns
Requirements are written in baseline names and follow only the rename mappings a reviewer deliberately committed. An uncommitted resemblance never satisfies a requirement, because the whole point of the mapping step is that a human took responsibility for the claim that two differently named columns are the same field.
Keep the list narrow. A policy that lists every column in the file will fire on every change and quickly stops being read.
Order sensitivity
Some consumers read a delimited file by header name and genuinely do not care about column order. Others, especially spreadsheet imports configured years ago and scripts that index into a split line, bind by position. Mark those as position sensitive and a reordering becomes a blocking finding for them and an informational one for everybody else.
Extra-column tolerance
An added column is the change most often assumed harmless. Name-based importers usually ignore it. Strict template merges, fixed-schema loaders, and anything that validates a column count will reject the file outright. Record the tolerance per consumer rather than deciding once for the whole handoff.
Two worked examples
A monthly finance workbook that imports by position with a fixed set of required fields: a reordering is a blocker, an added trailing column is tolerable, and a renamed identifier is a blocker until the rename is confirmed and the workbook is repointed.
A label merge template that rejects unexpected fields: an added column is a blocker even though nothing was removed, and column order is irrelevant. These two consumers can disagree completely about the same file, and both can be right.
Then test the real thing
An encoded policy is a model of a consumer, written by a person, and it can be wrong or stale. Use it to decide what to test, not as a replacement for running the actual workbook, import, or merge against the candidate file before accepting it.