I disagree. It seems to me the writers have teased us with far too many questions and far too much incomplete background material on Erf and its origins, history, and mechanics for Erf to be so small that Parson could break it with one exploit. I think we're going to need a lot more PLOT, more than two books worth, before we've exhausted this background, and this means a lot more exploits for Parson to find. IIRC, Parson only began at 2nd level, so he character has a lot of room to grow, and GK was only one of 10 cities the Tool, as one of an unknown number of sides, used to control. My guess is that GK was only the intro sortie or chapter, and there's a lot more of Erf to discover.
Agreed.