Besides, this isn't a discusison about designations, but about the BAe 146 in general (check the title of the thread).
Why, thank you. It does seem to be you getting wrapped round the axle of designations but hey-ho.
As your ightly point out the
146M is the CC3 in RAF parlance - and I'm not sure how much of the 146M appeared in the CC3
But to bring the topic back on track, as a tactical AAR asset - pointless. The cost of conversion of the aircraft into a refuelling role would make it very expensive. Why wouldnt you just use the A400Ms you already have on order, that come ready plumbed for AAR and just buy the AAR kits to meet your requirement for a tactical tanker.
Edited for wrong link