A depreciation method. An in-service date. A useful life, a location code, a parent-child relationship. Each one reaches forward into the general ledger, the tax return, the audit binder and every future transaction against that asset. Move one carelessly and nothing breaks today — it breaks in year four, in front of an auditor, and the person who made the call is three jobs away by then.
Which is why I refuse to treat fixed asset data as a spreadsheet exercise. Mapping a field correctly means knowing what that field is for, and caring enough to ask the question before the load instead of after it.