Split the account by who signs the check, not by visa category
An individual paying from savings, an employer paying from a budget and a relative paying from abroad are three different buyers, and one campaign hides all three.
Family-based work is usually bought by somebody spending their own money and comparing two or three firms. Employment work is bought by an HR generalist or an office manager who wants a process and an invoice. Humanitarian matters often reach you through a relative or an advocate who is not the client at all.
Each wants a different landing page, a different opening line and a different next step. The individual wants the fee. The employer wants to know your turnaround and whether you can handle several files at once. The relative wants to know whether you will even speak to them.
Structure should follow that split: separate campaigns, separate budgets, separate negative lists, separate reporting. Blended cost per lead across all three is a number with no decision attached to it.
Which one you scale is a capacity question. Buying employer work you cannot staff by Friday is an efficient way to make an enemy in Brentwood.