I have never liked assist for just that reason, it's slow. Your /petattack can occur before the assist registers. Change to

Code:
/petattack [@pettarget] [@target] [@focustarget]
Pick a conditional or use more than one. Vyndree had a nice one that allowed you to send your pets against different mobs, and as each mob died that pet would go help another pet. Some searching http://www.dual-boxing.com/showthrea...et+assignments