I'm not sure you are quite running the scenarios back and forth.Sorry but those builds are just dumb. I cant help but shake my head at how people try to build Mon Karren.
If you have XI7 you need either 1 acc or Intel officer to hit the brace. Mon Karen is almost useless in this situation, well it will prevent reidrecting 1 point of dmg only if the defender has and decides to use contain. That costs you 8 points.
If you shoot something smalelr like a Crovette XI7 the redurect acc/intel evade, if 1 evade is left unblocked defender can use it anyway and Mon Karen does nothing again.
With every other upgrade restricting use of defense tokens MonKaren loses value. In some rare cases it may do soooomething but remember that you pay 8 points for it on top of other upgrades,
1. Intel Officer won't stop the brace. Intel Officer works most efficiently when you can use a smaller hit to drop the toekn but it requires a deft hand since too small of a hit and they won;t use the brace and too big and they'll use it anyway. Putting Intel Officer on the big ships is good, no argument from me, but in my experience it''s been a 50/50 where the Intel Officer has been useful since with my style of play by the time the MC80 shoots it doesn't matter if they brace or not, its a killshot.
2. In your contain example run your scenarios to completion with and without MK. If you opponent uses contain you push more damage though to the same hull facing effectively making MK a cheaper spinal armament. If they use the redirect they are only saving them self from 1 additional damage from the hull zone you targeted. Mon Karren is insurance against not rolling an accuracy. It almost operates like a pseudo accuracy.
3. Even against a corvette, MK still let's you push one more damage onto the hull zone since they have to either redirect or evade. One more damage point on a corvette is a big deal.
As stated before, The MK/XI7 combo lets you push at least 1 more damage against the majority of targets out there. 8 points might seems a little expensive for another point of damage but that is going rate, ala Spinal Armaments are 9 and EA is 10.
MK is good just not OP like everyone thought when they first saw it. NOW MK and HTT is pretty worthless...
Not just that, but in subsequent rounds of combat, missing a XI7 means that your opponent will suffer much less damage.
Damage example:
http://lkhero.blogspot.com/2016/08/armada-making-liberty-work.html
Example #1 - Shooting at ISDs or MC80s with Mon Karren and XI7s.
Round #1 - Let's say you roll 8 damage. Regardless of ECM or accuracy, you IO the Brace. He has no choice but to Brace and take 4 damage directly to shields. If you did 9 damage and there was a crit, not only would he be unable to Redirect, but he would also take the crit because he can't Contain.
Round #2 - Second round of combat without the Brace available. Let's say you make the same roll. He can only choose to Redirect or Contain, but since Redirect will only negate one damage because of XI7s, he wisely chooses to Contain, but eats 8 damage directly to hull. Since you IO'd the Contain, it is gone for the rest of the game.
If you don't buy XI7s with Mon Karren when shooting at a ISD-II with Redirect, GL doing solid second round damage before he MAULS you in return. You're literally looking at doing near or full damage to hull vs. doing half that because of Redirect. On a ship that's absolutely meant to do damage, and doesn't have much survivalbility once it does enter equal-brawl range of the bigger ships, you better be making every shot count.
Hero, arguing that x17s help you survive for a second shot is absurdly obtuse.
But that is exactly what you just did.