Stormherald - mace talant stuns + metagem stuns + coh stuns = every ~5 secs enemies get stunned, also count charges and intercepts. Also count 61sta boost+ slight armor and dodge that agi gives. You bcome a head pain for your enemies.
Bloodmoon - no stamina, lots of crits, but as you know well geared players have 400+ res that absorbs crit dmg and decreace ur chance to crit on them. So the axe isnt realy usefull. Didnt c any top arenas warrior with axe spec.
Now the lioheart - yeah baby! Sword spec ftw, awsome bursts, fear resist +tallants= ftw. But no sta, no crit, no control(compared to the mace). But anyway its ftw.
Yes, its hard to decide what to use. You should take in mind your arena mates. If u have enough instant controls like mages, drools or rogues go for sword otherwise mace. Quick bursts pwn with sword.Its about 2vs2.
3vs3 and 5vs5, mace stuns save lives, its about tactics and controls then damages.