Most local boards have one or more merit sources. I even think that theymos emphasized that every local board has at least one active member as a merit source.
This certainly helped many members to upgrade their rank, even if they are not skilled in the English part of the forum. So, it's quite possible to gain a lot of merits, even if the user does not know much about the basics of how the forum works.

A similar thing is with the signature. Just about this case, if I'm not mistaken, for example, Agbe is very active in the Nigerian part of the forum, I don't see anything wrong with promoting a service there as well. Nevertheless, Nigeria has one of the largest Bitcoin ^crypto communities not only on this forum, but in the world, and it is certainly good for any service to be recognized by them.