; (E) integration of the work flow and interrelationship of the production process; (F) the consistency of the unit with the employer’s organizational structure; (G) similarity of job functions and work; and (H) the bargaining history in the particular unit and the industry. To avoid the proliferation or fragmentation of bargaining units, no employee shall be excluded from the unit unless the interests of the group seeking a separate unit are sufficiently distinct from those of other employees to warrant the establishment of a separate unit. Whether additional employees should be included in a proposed unit shall be determined based on whether such additional employees and proposed unit members share a sufficient community of interest, and when considering or deciding to include such additional employees in the proposed unit the Board shall give no consideration to whether they share an overwhelming community of interest with proposed unit members: Provided , That when evaluating proposed accretions to an existing unit the inclusion of additional employees may be based on whether such additional employees and existing unit members share an overwhelming community of interest and the additional employees have little or no separate identity.