I used to be a tank crewman. I love the tank. The M-1 is 68 tons of security.
But you know what?
The guy I hung out with in Germany who taught me most of what I know about combat has made his entire military career being a mortar crewman in armor units. His California guard unit was activated to go to the sandbox, and his guys were exited. "Yes!! We get to paint our tanks brown and go blow some stuff up!!" WRONG. They didn't need armor. They have little use for the armor that's already there. Too big, cumbersome, and VULNERABLE. (One molotov cocktail might not be a big deal to armor, but TEN is a VERY big deal.) They left their tanks at home, and the sole infantry platoon in the battalion, my friend's 11Cs, got to take the lead in reminding the tankers how to rely on basic infantry gear and tactics.
Again, if you ever actually have to USE your sidearm, it means all other systems, air support, heavier weapons, WHATEVER, have failed or are somehow not helpful in this case. This is the situation, MORE THAN ANY OTHER, when you absolutely must have the very best gear possible.