210,000 Marines including reserves.
99% of Marines answer to other Marines and don't have to wonder if their next paycheck is coming in. They also don't have to worry about their pay just being cut willy nilly or if the day they ride into Camp Pendleton at 530 is the day they eat a bullet.
When you're a marine, you usually get a heads up of when you're going into harm's way. You also have clear rules of engagement and a chain of command authorizing specific applications of lethal force. Cops are finding out that even following their training can get them charged with capital murder if they're forced to defend themseleves.
800,000 LEOs in the country.
Cops answer to local, state, and national bureaucrats and politicians. They also know better than most that the cops who place the highest value on their team and suboordinates well-being don't necessarily get ahead the fastest.
In fact I wouldn't be surprised if it was easier to be promoted if threw your suboordinates under the bus and cashed in all their good morale to get promoted and then make the next person clean up the mess you deliberately made.
My point is that it's an apples to oranges comparison.