You definitely need more STR, and if you can't hit IC, forget about the last 9 points of DEX, those use up too many stat points. Put those in STR instead. Get a Dark Frame armor, or simply use the Sasquatch, since both are 20%.
What you can do is, approach enemies that aren't clumped together, use Blade Stop, then proceed to Asura, and find a place to recover. It works well too for Champs with low Job levels (i.e. Not enough bonus stat for IC).
That's what I can tell you from my limited experience with LHZ3 Champ.
Thing is even without IC I can Asura the enemies FINE. it's just I can't cap enough damage to friggin finish off the stupid LK in one shot! I should be able to! RAAAGH!!
Yea that's why I said, if you don't hit IC, don't put the last 9 points of DEX, as you're just making it an unfinished job. Instead, put those points of DEX, into STR instead, like 17 more points of STR. Always maintain your STR in multiples of 10 for the breakpoint bonus damage.
That's one way of how you can increase your STR points by sacrificing another stat. Another way would be to sacrifice your INT by a bit, put more points into STR and wear Sasquatch/Dark Frame armor.
Another way is, simply avoid the damn Snipers =p If Cecil goes into Berserk mode, she knocks people out of Pneuma so I usually just run when she goes frenzy. Make sure you know how to form a Pneuma web so it catches you even if you fall out of it, since you'll be losing the 10% from the Pest card, you'll need to take more hits in order to Status Proc her.
Your main problem is not having enough STR, and from the way I see it, the stats eating up those points are DEX and INT. So those are the few points to address the things which I think are the problems of your Asura damage.