Compared to their information-gathering ability, the Organization of Water is better known for its combat strength.
In the Cicero Family and even the entire underworld, what was the Organization of Water's claim to fame? It was the one-strike elimination of the Fearless's lair, a victory achieved through brute force, so the Organization of Water's combat strength must be at least above average.
With Justin, the Organization of Water also took care of Mihali's matters pretty neatly.
Now, what does Justin want to do? He wants to ascertain the true whereabouts of Deyo Marcel, while Deyo is looking to hire mercenaries to bolster his strength—what is this if not an opportunity?
To put it bluntly, Justin simply wants the Organization of Water to act as undercover agents.