Plaintiffs’ lawyers battling BP Plc in the oil-spill litigation may be united in the desire to make the company pay, but they’ve started fighting over whether to try to rein in Kenneth Feinberg, who runs BP’s $20 billion oil-spill victims’ compensation fund. One group of lawyers, comprised of the 17-member plaintiffs’ steering committee, appears to be concerned that Feinberg will draw many more claimants into his fund...