When we hear of someone fishing for something, it arouses suspicion. It may indeed belong to Jesus' sense of humour that he uses the image. It sounds like one of his quips, a play on the image. As such it needs the broader context of Jesus' ministry where more adequate images will unveil a mission that is based on compassion and love. Without the broader context of Jesus' teaching the image is of ambiguous value.
People do sometimes feel like hooked fish, scalps.
The fallible Peter has always had fallible human beings as successors, bearers of the tradition, formal and informal, structured and unstructured. Despite signs of legendary development the bearers of the Jesus tradition never divinised Peter. The best traditions let it remain so. They also affirm his role and the continuing role and need for leadership and its accountability in the church. Ultimately Luke is linking that leadership to Jesus' own leadership and mission declared before his home town synagogue.