The annual tradition of the military services budgeting within their allocated allowances only for the service chiefs to submit “wish lists” to Congress of items they would like to spend money on is not helpful when the Defense Department’s top line is stagnant, according to Pentagon budgetary officials.

The practice of submitting unfunded priorities lists goes back at least 20 years and can help lawmakers identify where the individual services feel squeezed and where available funds would be most welcome, Pentagon Comptroller Mike McCord said Monday at a forum on the fiscal 2017 defense budget hosted by the Center for Strategic and International Studies in Washington, D.C.

Less useful is the game the services play of submitting their lists to Congress and Defense Department leadership, then almost immediately leaking them to the press and public, he said.

“It has its good and its bad points,” he said. “It is disappointing that these lists get out so soon before the secretary has had time to review them.”

Together, the four services in fiscal 2017 have compiled lists totaling 18 billion. The Army is asking for $7.5 billion primarily for purchasing more rotorcraft it cuts from the budget to pay for near-term readiness. The Navy’s list is next largest at $4.9 billion and also includes aircraft like the F/A-18E/F Super Hornet. The Air Force’s unfunded list is about $3 billion and includes restoring purchases of the F-35 Joint Strike Fighter that were put off to later years. Finally, the Marine Corps’ list sits at $2.7 billion and includes both fixed wing and rotorcraft.

“The problem is there is an agreed-to top line,” he said. “If you picked something off of the Navy list it would have to come at the expense of somebody else and we have already had well thought-out discussions within the department about what our priorities are…Absent some unusual change in the budget situation, it is less helpful this time than usual.”

Both Congress and Chairman of the Joint Chiefs of Staff Marine Gen. Joseph Dunford are mulling the lists. Dunford is expected to make a recommendation to Defense Secretary Ashton Carter about how to address the unfunded priorities, said Jamie Morin, the Pentagon director of cost assessment and program evaluation (CAPE).

As aviation is a capability much loved by the defense budgeting committees, it is likely that cutting aviation deeply to cover other costs in fiscal 2017 could pay off for the services. The final draft of the current fiscal year’s budget included increased procurement of almost all the platforms that were cut in the fiscal 2017 request: F/A-18 and EA-18, F-35, F-15 modifications, and UH-60 Black Hawk helicopter.

In a hearing last week, House Appropriations Committee Chairman Hal Rogers (R-Ky.) all but promised the committee would not cut Army aviation to the degree service leaders had budgeted.

“You don’t really believe we’re going to go along and cut aviation 35 percent, do you?” Rogers asked acting Secretary of the Army Patrick Murphy and Army Chief of Staff Gen. Mark Milley, who were testifying before the HAC defense subcommittee.

Congress is likewise fond of shipbuilding accounts and likely will protect them, though the Navy’s ship procurement programs are generally flat in fiscal 2017 compared with the enacted funding levels in the current fiscal year. In 2015, Congress also bumped up ground system procurement request by 11 percent in its fiscal 2016 appropriation.

Congress has an important role in providing civilian oversight to the defense budgeting process, and the services can aid their deliberations by laying out their unfunded desires, said Assistant Secretary of Defense for Strategy, Plans and Policy Robert Scher. But, he cautioned that any significant change risks upsetting the balance of investment with risk that the defense budget spreads across the department.

“Every individual decision is useful unto itself, but if you can’t balance it against the entire portfolio and understand where you are accepting risk in a zero-sum game, then that is not as useful,” Scher said. “That is what we spend months doing, is trying to allocate risk across the portfolio in the best way the secretary thinks.”