Higher level enemies with lower level characters?

I've seen missions where the enemies were all set to say, level 52 but the minimum level for player characters was around 45th.

How did the mission designer manage that?

I have reproduced the type of situation you're describing--I've now got an unpublished mission that in testing gives an entire map full of high level +10 mobs. But since the only application of it that I can see is even more egregious farming than is already being done, I'm not inclined to share it on the forums.

I personally consider this kind of "field of uberpurples" mission to be a potential game-breaker--but as the devs are soon going to be giving much more flexibility in difficulty settings than is now possible, perhaps they don't care about this kind of thing any more. And given that what I did wasn't particularly difficult, I'd be a little surprised if they weren't aware of it already.

But I wouldn't presume to read the dev's minds on this. If the devs A) aren't already aware of how to do this and B) are still interested in limiting the ability to do this, they should send me a PM and I'll explain what I did so they can consider ways to plug the hole. It shouldn't be particularly difficult. If I hear from them that they don't care whether this kind of thing happens or not, I'll post it and y'all can farm your brains out. If I don't hear from them, which I think is the likeliest outcome, then this is pretty much all I've got to say on it.

The method of doing this will not be possible in issue 16. There are two methods of doing this. The first method, which is the one I think yasfan is referring to is more of a 'trick', and so I think witholding this one is a good idea.

The second method was a feature added to issue 15, and I have no problem mentioning it as it was intentionally put in place.

If you look under mission parameters, you can set the minimum and maximum level of your mission, which also affects the team's level range. One other point to note is that your difficulty settings have an impact as well. For example, at +5 difficulty, the minimum SK level is actually 2 levels under your set minimum level, while at +3 or +4 it is 1 level below. Therefore, you would want to set your minimum to 47 if you intended to SK to 45.

This practice is not common as fighting +7s is not easy and will most likely frustrate anyone lackied to this level. In short, if you're looking to design something that is team friendly, this is a very bad idea. You'll see this in chat:

"Hey I hit him! For like 1 damage lol"
"LEEEEROOY JENNNNKINS!!!!!111!!!!"'
"Rez PLZ"

Well the "application" that I am trying to use it for is to easily test my scrapper's defenses against enemies of progressively higher levels in order to determine what the cut off point is in how much damage he can take vs differing level opponents.

Being able to just reset a mission in AE is far simpler than running all over different zones and trying to find just the right group of enemies in the numbers I am looking for.