As long as global moderators can handle it, it is no problem. Not only on altcoinstalks, even on other crypto forums, global moderators can handle spam cases on no-moderators sections. But it can be a problem if many global moderators are not active for some days, or rarely log in to the forum. Then, who will handle the cases? Well, the best option is indeed to have a moderator on the section, especially on the section that most forum members spend their time posting there. Anyway, what section do you mean, mate?