I'm brinning up this thread to add an option.
Above I suggested to fix the problem of connection between the plot and the amount of space through adding some space. But recently I realiesed that it actually could be fixed the other way around.
Suggestion:
Replace the fact that goblin scouts cannot find the grove and report to Minthara with the fact that she's well aware where the Grove is, but she doesn't "want to lead a suicide mission" so much that she's forcing them to find some additional path inside. This will only need some fixes to the dialog with Minthara and the prisoner. Also would be better if Minthara would actually expect us to do some sabotage work in the Grove, before starting the siege, and we could lie to her about our accomplishments if we are willing to lure her in the trap. For example she could expect us to turn off traps in the tunnel and then she would send some forces through the tunnel.
