Wrong. Hrok got his positions - and gold - after he stepped up to become Banker. His position as Banker has allowed him to claim insane things as under his jurisdiction -- everything from trade to dereliction of a lord's responsibilities have come under his domain of power at various times.
You requested money for your unit? Hrok knows your income. Hrok knows you've you been wasting your gold; no money for you.
Failed to make even a token effort at feeding your own region? Planning rebellion against the crown? Hrok has shot them down.
In fact, unless I'm mistaken (please correct me if I am, Delvin/whoever), Hrok has been - through his position as Banker - directly involved in every single Lurian exile for the last two years. The trick is to realize that, like in the real world, you can distill any situation down to one single element: money.
And it's the Banker's job to control the money.
Couple of things, the game does not in any way portray the idea that the Banker's job is to control the money. Not saying its bad for you to make it your job, but thats false to say it is. Knowing people's income is something everyone can know with a bit of work (and almost none for those above knight) and whether or not they wasted their gold is not something being banker affects. As well, related to my first point, the ability to become powerful in certain, rare circumstances, does not equate to the position having the ability to commonly become powerful. You being a great player and making it possible is great, but you can't be like I did something so everyone else can too, the position is fine. Vita's examples cover things any banker can do, thus great examples. Thinking of it in a bit of statistical manner, your case would seem to simply be an outlier, perhaps with lurking variables that caused it, but nonetheless looking at bankers overall, an outlier. (I did say seem covering myself in case I somehow turn out to be wrong btw).
