@Michael S. They don't: find property, process the assumption, transfer a loan, guarantee anything.
They do take a $5500 nonrefundable fee and 1% buyer side commission so as an agent I can't see how you would try them out as you will need to cut your pay. The servicer may have their own fees, rules, and disclosures.
Agent crosses a line to disclose rates, legal ins and outs, terms, and disclose the loan which even a broker license doesn't cover. Agent is also responsible to disclose to VA seller that they will lose a percentage of their eligibility and the loan might show on their credit after the fact.
Servicer isn't set up with lots of staff processing so the buyer needs to turn in their whole financial history for the past two years in one email, don't trickle in papers they get lost. Owner occupied only.