The question to ask before entering one at all

What does this arrangement do that we cannot.

The strongest arrangements answer that question specifically: access to a market, a physical location, a language, an existing relationship, or a capability the principal genuinely lacks. Those are durable reasons and they survive scrutiny.

The weaker answer is volume, meaning the arrangement exists because it produces more clients than the principal could reach directly. That is a legitimate commercial motive and it carries the highest risk, because nothing in it requires the partner to be good at anything except recruitment.

Where the honest answer is volume, the arrangement can still be sound and the monitoring has to be built for that. Where the answer is a genuine capability, the monitoring can be lighter and focused on what the principal cannot observe.

It is worth writing the answer down at the outset and revisiting it. Arrangements entered for a specific capability frequently drift into volume relationships over years, and the oversight designed for the original purpose no longer matches.

The other question worth asking is what the partner gets, and whether it is enough for them to invest in doing it well. An arrangement that is marginal for the partner will receive marginal attention, and no amount of contractual obligation changes that.