How do your Action Scenes end?

I've been playing for a while and I know others here have as well, so I was interested in gathering some info on Action Scenes.

In my group, we played the full Starter Kit and we've played 6 sessions of our own game.  

In all those Action Scenes, never once has a PC gone Out and we've only run the Scene Tracker out once because I gave the villains ample abilities to speed it up.

There have been a couple times in scenes when I could have ganged up on a hero to take him or her out, but I didn't.  Usually one or two (out of 4) are in the Red, but they stay standing.

I guess I'm wondering: is this "normal" in your own experiences?

Until it was the final boss fight of my last campaign, there was exactly one instance of a player getting incapacitated.

In general, my players routinely finish in the Tracker's Yellow with new damage in minion/health heavy scenes, and in the Tracker's Red without much new damage in overcome heavy scenes. In a mixture, it's somewhere in between the two.

My players typically don't get incapacitated unless they start working independently as opposed to working together.

Spoke too soon, I guess.  Last night, for issue 6 (i.e., end of a collection), I used a Difficult Scene with an Epic Scene Tracker.  We're halfway through, 2 of the heroes are down, and the other 2 are trying to stay standing so they can lose by Tracker rather than going Out.

The Scene is 4 Difficult Elements:

1 Villain w/Upgrade

4 Standard Villains (2 Moderate = 1 Difficult)

1 Environment (mostly hostile)

I had the Upgraded Villain flee the scene when he almost went Out.  I had another Standard Villain leave when I realized I didn't need him for villainy to win the day.  It's 2 heroes vs. 3 villains, but the heroes are ragged.

Side issue: balancing villains is difficult.

Side issue 2: In a tough fight, if the heroes aren't totally on their teamwork game, things go south fast.

Oh definitely. I at one point had an Overpowered Titan Villain, and it just tore the heroes apart.
Edit: No upgrades even, just a reaction, an inherent, and two action abilities. It was horrifying.