Lol you can always glitch aps in tiger form thoughhhhhhhhhhhhhhh you can't exactly get back out of it unless you relog so you can't use any skills and it would be totally useless but would annoy ppl xD
On topic note, DPH wise (cause I personally think aps barbs are stupid unless you wana troll ppl, personal opinion though) Sage is gunna hit harder due to Sage axe/hammer and Sage SoT and in tiger form they'll have more hp to boot, but a counter to that is alot of the demon skills are better like bestial onslaught and as stated before mighty swing, tbh even in tiger form I like the demon skills more. So in all honestly in a DPH fight it's gunna go down to (if there is even a winner) the one with more skill xD
Another note is generally a DPH barb utilizes Arma so the more hp you have the better when it comes to that but again Demon Arma is stronger and with bestial onslaught higher chance to Zerk Crit, Sage arma only reduces the hp you lose from it. Demon Blood Bath 300% acc but you lose more hp then Sage, Sage only loses 5% hp but 200% acc. I'd say as far as Balance Demon/Sage on barbs is most balance out of all the classes (personal opinion)