Split the account by urgency before you split it by visa category
An emergency inquiry and a planned filing behave so differently that averaging them in one campaign makes both look mediocre.
Urgent work arrives with a deadline attached: someone detained, a notice with a date on it, a status about to lapse. Those searchers convert fast, tolerate a higher fee, and disappear within hours if nobody answers. Planned work, family petitions and naturalization among them, arrives calm, shops longer and often talks to three firms.
Run them as separate campaigns with separate budgets, separate ad copy and separate landing pages. Urgent campaigns get call extensions, tight daypart control and the highest bids you are willing to hold. Planned campaigns get lower bids, patient budgets and follow up built into the offer.
Only then split by category. Within each urgency tier, group by benefit type so the ad can match the phrase and the landing page can match the ad.
Blending them produces the classic bad report: acceptable cost per lead, terrible cost per retained matter, and no way to see which half caused it.