Best Methods to Estimate Salespeople Count by Company Domain

I want to get the number of salespeople at a company given a list of company domains. What is the best way for me to do this? I’ve tried Find Employee Headcount by Criteria, based off of either Domain or Enrichment by #employee_count, and I’ve gotten very different results depending on which one I use. I am looking for a comprehensive method that will give me the closest estimate to the number of salespeople at a company, and a great bonus would be if there was some way to access this list of salespeople to be able to contact them.