The issue with the cockpit 'glass' was that Tan thought it would be as easy to destroy as in a civilian vehicle, so that her weapon would have shot through it and into space without any problem. It was really made of advanced meta-materials that don't melt until they're over five thousand degrees or something, and disperse heat very well, so the radiation that was reflected or absorbed and scattered back, even in a split second, was enough to kill Victory, who was unarmoured and less than two meters away.
So... if Tan had an axe or a hammer, she would have charged up, swung it at the 'glass', had it bounce back in her face, or get stuck, and while no one would have been injured by that, they'd both have crashed into the planet at a few hundred miles an hour, and been badly injured or died (since the only reason Victory survived the crash in the alternate timeline where Tan didn't try to rescue her first was because she was securely buckled in. ...that, and Nekos are really good at surviving crashes.)
I don't think there was any way to 'just' break through the cockpit, it was way too durable. Now that Tan knows that, she knows that she should have risked injuring Victory by carrying her out the back of the shuttle, instead of trying to save trouble by going through the window. A weapon that's absurdly sharp might have done the job, though.
(Also, you mean using the flagpole as a martial arts weapon?)