I'll also add that even if you skip joining the Fabulous Five, Arhu does indeed offer help on his monstrosity if you go and ask. You get the quest started by entering the cave and talking to the desperate recruits, and if you go back to Arhu, you can indeed talk to him about the Sparkmaster and he'll offer you help.
The Fabulous Five recruiter is a salesman for a pyramid scheme, so of course he's pushy, aggressive, and obnoxious.
