There's a fight in Old Seb for the 1.5 where you can very easily kill the mob you're supposed to be testing your axes on (read: waiting for emotes and need the mob alive for) if you're overlevelled.
My redcents would be zerk, rogue, or ranger as well. My group is the same as yours, but with SK instead of WAR, and rogue as the 6th. I enjoy the diversity, but that's a personal preference. SoS also helps make the rare corpse runs and collectible farming a ton easier. My first eq main was a ranger though so I always have a soft spot for them though. I don't think you can go wrong with any of the 3, it just depends on your motivation:
Zerk = optimized dps
rogue = close to optimal dps, SoS utility, fulmination from poisons (but I'm too lazy to do this and stuff dies quick enough anyway)
ranger = buffs your melees, more utility than rogue, HS (a teensy bit situational for me. I don't think a ton in the last two expansions are headshottable but someone can correct me)