Barb is a *horrible* tank for elite vod/tod now no matter how well geared. A human barb with huge healing amp *might* be able to pull it off with limited pot/scroll usage but is still far from being a good tank. Or even what I'd call "a tank".
Seriously, just run hard if you only have a barb or something similiar for tanking, both Suulo and Horoth are shredders on elite these days.
If you suspect that the group cannot complete the highest difficulty setting without resource usage, then why insist on running it on the highest difficulty?