Sounds like a great idea, and I'd love to try something like that. Unfortunately, the combat in the WFRP system is so punishing that casual fights just can't happen. You can get an injury with one attack from a basic 0-level brigand that sidelines you for weeks of the campaign (if not permanently debilitating you or killing you outright). As a system, you just can't use it for action-based games like Pathfinder or D&D.It sounds like they want to fight and not be poor. Reward that. Give them fights between the investigation. Link it to the plot if you like and put coded messages on the attackers. Introduce a patron that promises money and increased class rank. Have the patron request increasingly terrible things from them that makes them question the purpose or motives. Let the patron betray them and leave them for dead, inspiring their investigation to reap revenge and topple someone who has wronged them, but they cannot do it without proof.