Couple of things I would like to add.
Mileage's for a set of tyre's will vary between members as the driving habbits will also be different. (Lets face it, you dont buy the MV6 version if tou want the encomy and performance of a 2.2 tractor)
Also I have noticed I dont drive the Auto's as hard as I would do with a manual, whether it's just me I dont know.
Of the 2 cars I have the 2.5 has ZV3's all round and purchaed by me, but the car has only done 6000 miles in 2 years. Gets driven hard on occasions, can easily provoke wheel spin from a bend with the right buttons pushed, but not as yet had them break contact with the road under harsh driving in the wet or dry (Harsh but not reackless driving)
The 3.0 Elite has 2 different pairs fitted by previous owner (Makes unknown at this point) But I expect the tyres to last a lot longer as I drive the car completly different to the other. (Maybe it's coz the exhaust doesnt sound like an F1 car on full throttle like the other one.

)(and I dont use the Sport Mode as often

)
When I do replace tyres, I allways fit them in pairs and allways put them on the rear, moving old tyres to the front, if there is any odd wear on the fronts I allways put the rear with the least tread to replace it, till the tracking gets done.