For Sazabi, depends on what you want out of it. If you're going to spec bomb like its nobody's business to take advantage of Spec Up skill parts and the spec boost from Enhanced Funnels skill, putting points into spec isn't bad. Defense probably isn't the worst idea given Fortress, but you'd want to ask someone that actually has one.
For Exia and Kyrios, boost and reaction issues tend to be sorted out once Trans-AM kicks in, so you probably don't really need the points in reaction. Attack will work well enough for Kyrios since it has Potential skill, and its not like putting points in defense is going to help its durability much. Exia could work well with either Defense or Attack, whichever one's more of your style.