In constructing a hiring plan, you have to resist merely duplicating your department's historical configuration. Think instead of the hiring plan that will serve the department best over the next decade. You might try to project your department's schedule of retirements and separations to anticipate your recruitment rate. If you discover, for example, that you anticipate making a faculty appointment every other year or every third year, try to use that information to constitute a good hiring plan. Another way to maximize leverage for faculty positions is to build on partnerships.
Proposals are far more powerful when they are part of a plan involving several departments.
French, Spanish, and English, for example, might build a concentration in the literature of the Americas, or English and history might build a concentration in American studies. One might seek out partnerships with arts departments or with linguistics. The Italian department at Berkeley, for example, made a successful argument for a new faculty position after joining forces with scholars specializing in Italian music, history, and art to request a position in Italian studies that would serve a variety of interests. Administrators are responsive to initiatives that have the potential to energize teaching and research, particularly across several departments, and to attract students. Before you act to maximize your chances to obtain faculty positions, I would recommend that you step back to ask yourself a few questions.