actually it's not difficult to break 100% ArP in current gear. On a sundered mob I am well above 100% using an axe when grim toll procs. The only thing I see changing is exchanging grim toll with pyrite infuser and switching to a mace (possibly t2 furious mace this week, if i don't waffle back to the axe) and shooting for something like 75-80% static ArP on a sundered mob + the benefit or FF or shattering throw. also this was a TG thread, but since you opened it:
so some numbers supporting them in conversion to 'rating':
axe: ~230 crit rating, 5% crit damage (can't quantify that)
mace : ~184.5 arp, 26 exp rating (exp for humans only)
the raw stats you gain from axe far outweigh that of what you would get from mace alone. it's much easier to take the axe and then socket for ArP as opposed to taking the mace and then trying to back fill your gear to attain a respectable crit rating. also given overpower and juggernaut arms is built far more on crit, where the 5% damage increase comes into play. the main reason you took a mace was to straight stack ArP, which will no longer be possible.