The Scaven-pickers are a major sore in the sides of the Reservationghouls. Measles will explain to the player that half the time the Scaven-pickers show up in the Trading Post, something, or a bunch of things wind up missing. This doesn't sit well with Measles. Normally he'd just waste the ones that come into the Trading Post, but once wind of the slaughter hit the rest of the Scaven-pickers, Measles and crew could expect major retaliation. In addition, Measles has no idea how many Scaven-pickers there are, so he is afraid of "waking a sleeping giant."
Measles will take a chance on the player and hire him to find a way to get rid of the Scaven-pickers. Measles does not care how the player goes about this; he just wants it done, as long as there is no connection to himself and the Reservation. Accepting this quest will get the player access to the Town and Sub-Levels 1 and 2. Measles' thinking is that the player is working for him and he (the player) should have access to the ghouls' best equipment. Measles will also remind the player that he will be watched 24/7, so no funny business.
Of course, the player can blow everyone away at the Reservation and gain access that way, or sneak through the town gate, following the herded slaves, but that's a different quest.
Character type completion breakdown
Combat Boy - Take the straight forward approach – seek and kill. After accepting this quest, or after speaking with Klik and learning the Scaven-picker's language, a script flag is set that will allow the random encounter, Scaven-picker Camp Encounter, to pop up during world travel more frequently than "rare." The player will get this encounter more than once if he chooses to skip it earlier in the game, so there is always a chance to complete the quest. Killing all the members in the camp is the road to success.
Diplomacy Boy - This boy can take a more diplomatic approach. If the player learned the Scaven-picker language, then he can try to convince Klik to take her nomads to another location. By either lying and saying there is a great big stretch of land to the west that is covered in salvageable debris ripe for the taking and that they should go there to get rich, or by telling the truth and giving another location the player has been to and sending them on their way. With either choice the big cookie is that they would no longer need Rad-X and they would not need to interact with the ghouls.
Stealth Boy - Sneak into the camp at sleepy time (the starting point of the map should be far enough away to do this), slit Klik's throat, and plant the bloody knife on another Scaven-picker. When the tribe wakes up, chaos will ensue and will eventually break up the tribe. Or the player could do the "Sell smooch to the Scaven-pickers" way.
Science Boy - Science Boy can use a science kit and the recipe for Rad-X as a bargaining tool. The player will give Klik the science kit and recipe if she and her nomads leave the area of the Reservation. Klik may be weird, but she has honor, and she will honor a pact to leave for the recipe and science kit.