Do not assume they count. Have the actual relationship and relevant period assessed using the underlying facts, rather than adding every year of commercial association.
Resolve employment and knowledge separately
The applicant may possess relevant knowledge while still having an unresolved employment requirement. Identify the actual employing entities, duties, dates and locations. No amount of descriptive praise replaces a qualifying period that the facts do not establish.
Test the periods one at a time, in the order they occurred, and mark each as employment, as services supplied through an outside business, or as unresolved. What makes a period unresolved is usually the absence of the records that would settle it: who directed the work, who bore the cost of tools and staff, who could end the arrangement, and on what basis payment was made. Hypothetical example: a specialist who supplied a clinical-supplies wholesaler through an incorporated company for four years, then joined its payroll, has a long association and a short employment history, and only the second of those is being measured.
Do not merge the periods to reach a total. If the qualifying year is not there yet, the honest options are to wait until it is or to have another route assessed, and neither improves by describing the earlier years in warmer language. The year must also fall within the three years preceding the filing or admission, so an old employment period is not interchangeable with a recent one.