From what I understand the Bul Kathos weapon set fixes the problem entirely, but before then you will have issues. If you stack RCR to get the cost down you can't spend fast enough to cooldown Berserker enough to keep it up permanently and since all your fury generation while WWing comes from COTA ancients hitting targets not all characters ancients all hit at the same rate. It inevitably leads to different rates of fury gain for the characters.

Once you have full BK sets across all 4 chars it shouldn't be a big deal because they passively give 10 fury/sec. That combined with the ancients giving fury even if not always equal should be enough to maintain it on all 4 chars.

I am kinda burnt out on running teams that are that heavily reliant on a weapons though. I had tons of issues with my monk and sader teams in getting weapons for them. When the weapon is build defining you are stuck hoping they drop, at least with other slots they are 3 times cheaper to gamble so build defining items in every slot but weapon is not as painful to acquire in most cases. Trying to get two weapons for each character would be a nightmare if you aren't very lucky.

The real reason I don't want to play barbs though, is that they don't have a CC option that would work with a build. DH, Saders, WD, Wiz and Monk all have a CC skill that could be dropped into a build that makes fighting RG's much easier. Barbs do have CC immunity and very high toughness (especially with Ignore Pain Mob Rule in Round robin and Perma all rune Berserker) going for them so they are still appealing. I just really liked when IK was a pet set early on. That would have been much more playable than the current WW iteration it seems to be on (at least for multiboxxers... I can understand why some Barb fans weren't keen on IK at the beginning of the PTR).