Fort Liberty, formerly Fort Bragg, is a military installation of the United States Army in North Carolina, and is one of the largest military installations in the world by population, with over 52,000 military personnel
And since military people rotate in and out, the numbers who lived there at one time are several times that number.
The New Orleans guy was essentially a mild manner clerk turned jihadi after becoming a born again Muslim in middle age. In the Philippines we call this an amok killing; he was coping with anger probably from financial or divorce problems, and got recruited by the bad guys.
The Vegas soldier was special forces so is a puzzle. He would know enough to make a better bomb, and would probably know that the Tesla truck could have stopped the explosion, meaning that even using fireworks he would know enough to put them to explode the battery or raised them to spread the explosion around. So unless it was a protest against Trump or against one of the US wars, I suspect it was planned to make headlines but not kill folk.
What I can’t figure out is if he wanted to cause damage why did he park outside instead of just ramming the doors and then detonating...it wasn’t like he tried to walk away....so many questions