The arbitration provision in the workers’ compensation arrangement between Personnel Staffing Group LLC and Zurich American Insurance Co. unquestionably covered Zurich’s demand for $4.6 million in premiums plus a $39 million letter of credit — but Zurich and Personnel Staffing disagreed on whether it was broad enough to require arbitration of Zurich’s allegations, in a Cook County case, that Personnel Staffing’s payments of more than $10 million to its majority member and a corporation he …