Create New Job (Method Calls)

This may or may not be helpful, but since the orders already exist, have you tried just calling the OrderJobWizard BO?

warnings = "";
errors = "";
exceptions = "";

CallService<OrderJobWizSvcContract>( jobWiz => {

	try {

		//__ Set OrderJobWizard Dataset
		var ds = jobWiz.SelectAll(orderNum, true, true, true, true);
			/* Params: 
				int OrderNum, 
				bool CreateJob, 
				bool GetDetails, 
				bool ScheduleJob, 
				bool ReleaseJob;
			*/

		jobWiz.ValidateJobs( ref ds, out warnings );
		jobWiz.CreateJobs( ref ds, out errors );

	}
	catch ( System.Exception ex ) {

		exceptions = $"{ex}";
	}

});