~4600 hull FAS; module status at 19% hull after getting pummeled by Ashenfox's triple rail + dual frag Krait Mk II with instructions to try for module damage:
Nothing was repaired during the fight except the larger of my two MRPs and I had no TLB weapons in this engagement.
I am not remotely a good assault brick pilot and I'm still experimenting with loadouts, but even against the sort of setup Ramius has proposed, I do not see module damage as being the limiting factor, at least not without a lucky shot through the canopy. A good pilot in a quad penetrator rail phantom should best me, in this setup, quite handily...when the hull integrity on this FAS hits zero.
Anyway, we'll see for sure later. Maybe the phantom can open up a large enough gap and with enough penetrator rails damage MRPs faster than the AFMU can compensate, but I'm skeptical. For more general use, I might even dump the second MRP...most of my ships that can reliably power an AFMU through PP malfunctions only need one.