I would argue the author(s)' identity matters more in the case of such evidence synthesis reports.
In this instance the author rather than simply thanking his RAs for their assistance should have clearly outlined what particular contribution they made. By way of contrast in bio-medical journal reach articles and systematic reviews the specific contribution and role of all those who helped prepare the report is clearly outlined together with a relevant disclosure of any possible conflict of interest including funding. While the AEA does now requires authors to include the disclosures on competing interests, the practice of providing a summary of the roles and responsibilities of authors, particularly and especially RAs, is overdue.
Indeed in this particular case the author listed on the masthead should have clearly and succinctly delineated the role and contributions of his two RAs in the evidence synthesis. If past experience is any guide the RAs did provide more than token assistance.
By way of example here is a typical statement on authors' contributions contained in a biomedical journal (an open access article available from Biomedcentral) where the authors' named have been abbreviated to their initials:
"BS designed and conducted the study and wrote the manuscript. MB, JG and LB participated in the design and coordination and assisted with writing the manuscript. CH and AP carried out the quality assessments and assisted with the writing. NA assisted in the conduct of the study and commented on earlier drafts. GW assisted in the design of the study and commented on the statistical analysis. PT helped with the design of the study and assisted with the nominal group process. All authors read and approved the final manuscript."