|Mathwei ap Niall|
Uh, thats a nice picture, but I'm very fond of my familiars and would stand between them and harm. You know, you are closer to the front, hopefully monsters go after you rather then him (Since he has half your hp). Besides if your familiar gets killed, there goes all future cdg attempts till you get a new one.
The arguments against this are the following:
1) Some GMs rule earth elementals cannot use weapons. Can understand that, in which you need to try to find a way to get cha to 13, take evolved familiar to grant reach evolution. So the earth elementals slam has 10 ft reach. Sadly cdg dmg will drop to only 2d6+14 due to natural weapons only having x2 crit.
Make DC 10 + 2d6+14 fort save or die. Ill omen was still on, no? Guess they need to save twice, take lowest, then. At lv 6 hexcrafter, the damage increases to 2d6+20, as per scaling with power attack. With mauler archtype you might be able to improve on the str part.
2) Some GMs say you can't put living things on a floating disk. This to me, doesn't make sense. You can put a dead body on the disk, but not a living one? Or that staying on a floating disc eats your move action (but hey, objects don't hate move actions to lose and still can remain on the disk!) If GM forbids it then, sorry, whole idea won't work.
That's why you don't use a familiar for this tactic, you purchase a Homonculus. All the perks of having a familiar with none of the downsides and at only 4K a pop you can always have 2-3 of them around at a time.