Randy, I have had no luck attacking buffs from below. As you are pulling up you are decelerating. If you are diving down you are accelerating so you are in their guns too long from below. Every one of my attacks are from 3.0 Icon range or more before I turn to attack and always always always from their 1:00, 12:00 or 11:00. I attack the lead first, and then try to get a few pings on their left or right AI as I fly past. I attack the lead first because if I only oil his engine, my next attack will always be on the AI's until they are dead. I do not attack the lead on the second and third pass when I have oiled his engine because in just a little while, he will lose that engine and his entire formation will slow because of it. This will make a huge difference if he is at altitude because he will slow down dramatically or have to start descending, making it easier on subsequent attacks.
If at any time you would like to ride along, please PM me and ask and I will be more than happy to have you ride along.