in the last 6 months the AC has issued more user bans than Jimbo did two years before that
Indeed. Most of them for a symbolic 24 hours. This is fine for regular contributors who occasionally go off the deep end, but that's not what most of the cases have involved. Wik's ban is over now, the only reason he's still gone is because he left on his own. Meanwhile Gohde and "Irismeister" are still up to their old tricks, exactly as before arbitration.
Are you volunteering to be a member of the AC?
No, I am saying that the concept of an AC has been tried, and does not work. I don't consider this to be the fault of the AC or any of the members of it, rather a problem with overall structure, confusion with regard to the amount of authority it holds, etc.
3 non-AC member admins to do such a block
This is a good idea, we've had five already in Trollkien's case, for example. As with all good ideas, though, it never seems to get implemented (didn't we first see this proposal months ago?).