Hrm... It's been awhile since i've played 15, but I'll offer what I can.
Personally I'd take fewer jacks and more infantry in the butcher list. Drop one jack. To get the most out of IFP you should take the UA, but at this level I may be tempted to switch out for min Kayazy plus UA. Either way if you drop jack and take UA you can take widowmakers. They rock on feat turn, and can put the hurt on anything if properly buffed. If you drop juggy that leaves one point, so I guess Reinholdt? If you drop Kodiak you can get a two point solo. Probably marksman, or man hunter.
For Irusk, you need a bit more help. I'm not a huge fan of destroyer on Irusk. He doesn't do enough to buff ranged attacks to make the 9 points worth it in a 15 point game. Irusk is about infantry support. I'd drop destroyer to a juggy to free up points. Kovnik is also a points sink. If you want a JM take koldun lord for power boost. Switching to juggy, and dropping Kovnik frees up 5 points. I'd max out Kayazy and take UA. Never take Kayazy without UA.
Kayazy with IF are sick. Standard trick is to run them up to enemy lines and engage them. Activate Irusk and cast IF. Kayazy are now def 19 vs melee, which makes the unhitable unless opponent can debuff them. Next turn cast battle lust pop mini feat, and go after caster and heavies. WMidow makers add some support, and juggy shields Irusk.