WASHINGTON — Former Marine Corps Capt. Greg Jacob says when women entered his company, everyone's training scores went up.

"The men didn't want to get beat by the women," he said. "So they started lifting more weights, pushing harder. The entire standard of the unit was raised."

That's why Jacob, a longtime advocate of integrating women into military combat posts, is frustrated with slow progress on the issue in recent years. He thinks the issue isn't one of political correctness and quotas, but instead one of re-examining ways to make the military stronger.

On Wednesday, Jacob was part of a group of advocates on Capitol Hill to discuss ongoing issues with women in the ranks, with a focus on the challenges still remaining 16 months after then-Defense Secretary Ash Carter announced plans to drop gender restrictions on all military jobs.

The move has been met with praise from equal rights activists and derision from some conservative groups, and has produced a slow and sometimes confusing mix of new integration rules for each of the services.

Already more than 640 women in the Army and 180 women in the Marines have entered previously closed artillery and combat engineer jobs, said Ellen Haring, retired Army colonel and a director at the Service Women's Action Network. Another 250-plus women in those two services have entered or finished infantry training.

She called those figures a positive step forward in a short period of time, but said military officials still need to engage in a host of other changes to ensure the success of future women service members and the overall health of the force.

At the top of the list of obstacles Wednesday was the Marine Corps' continued use of separate basic training courses for men and women, a practice which Commandant Gen. Robert Neller told lawmakers last month is under review by service leaders.

But Neller pushed back on congressional criticism that the training is "segregated" since some aspects of the training include both men and women. Under questioning, he acknowledged that the Corps’ practice is more separate than that of the other services.

Critics said the practice needs to stop.

"Our feeling is that in addition to giving sub-par training to women … they also come into a service where the message is sent — to them and to their male peers — that they are second-class citizens," said Gillian Thomas, a senior staff attorney at the American Civil Liberties Union.

"If from day one that inequality exists, then real integration is not ever going to happen."

The ACLU has had a lawsuit on military gender roles pending for several years, even after Carter’s announcement. Thomas said the goal now is to ensure fair implementation of the new policy. A court conference on the issue is scheduled for July.

Meanwhile, SWAN officials said they hope continued congressional pressure on the issue will force military leaders to move forward on improvements like better gender-specific gear to troops (like body armor and helmets) and re-examining training standards to ensure their relevance for all service members, regardless of gender.

They’re hopeful those changes will lead to broader cultural shifts in the military like the ones several women who have entered infantry roles have already seen.

Second Lt. Wednesday Nelson, a Colorado National Guard officer who was among the graduates of the first Army integrated infantry officer courses, said she saw significant skepticism from her male peers when she first started training, but gained respect as they saw her being held to the same standards.

Still, she expects continued pushback until women in infantry jobs becomes the norm.

"For now, anything you’ve accomplished or failed is always going to be focused on more than the men," she said.

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at lshane@militarytimes.com.