Merchant banks and merchant limit

Playing Venice now, and I decided to build some merchants banks across my kingdom, as I had maxed out my merchant limit. However, as I found out, the merchant bank(1st level) doesn't up the limit at all - all it does is allow a merchant just like the grain exchance, it does not allow one extra in addition to the grain exchange. Now I wonder, is this by design, or is it supposed to work that way? Is it supposed to do virtually nothing but add to trade(as you undoubtedly already have a grain exchance), or is it supposed to add a merchant?

Shouldn't be hard to change though, I suppose all I have to do is change the merchant limit of the 1st level to 2 and the second level to 3...

Well you could argue both sides. But they probably only added agent_limit merchant 1 to the first level to prevent issues cropping up if this level was lacking the limit but the next level would.

I.e. the first level is not supposed to give an additional merchant, only the second level does.