The biggest issue with the JMK team when using LV and Maul is the maddening amount of cleanse power the team has. A unit cleanses if they trigger the savior, mass cleanse when JMK ults, cleanse when JMK targets them, GK has a mass cleanse...
If LV's Dark Harbinger applied the debuffs in a semi-locked state like KRU's stun, that might make things a bit easier on offense. You hit GK with it, apply the BI and HI, knock him to 1 HP, trigger savior, and instead of him jumping to 50% health and protection with 50% protection up for his troubles, he'd just stay at 1 health and be killed on the next attack.
Being stonewalled by GK is very aggravating. A 4/5 year old unit heavily impeding the latest GL release.