Each needs a complete file of their own: a detailed employer letter naming the profession and the specific duties, proof of citizenship, and credential evidence in the form that profession's listing accepts. Copying one partner's documents into the other's file does not work.
Build two files, not one shared package
Organize each professional’s citizenship, duties and credentials so the records can be assessed separately. Translation and credential evaluation are distinct services; determine what each actual qualification and procedure requires. Use shared household records where relevant or requested rather than assuming they must always be excluded from a principal’s file.
When an engineering-services firm places a Canadian engineer at a U.S. client's plant, the TN application still names the firm as the employer. Resolve the discrepancy with the relevant employer source and use an accurate account of the agreed terms. Use concrete work products to explain the duties and compare them with the listed profession. A letter that opens with an internal title and then describes crew scheduling, equipment purchasing and client billing invites the reading that the role is management rather than surveying. Resolve any difference between the offer letter and a separate support letter before relying on either. A common error is submitting an allowance schedule without a complete offer, leaving no proof of prearranged professional work.