The Japanese bullet point for 'single-handedly' doesn't mean anything like 'attacks single targets only'. It just says they put out high damage all on their own, i.e. they aren't a support role and aren't especially reliant on other jobs. I'm imagining them chaining things together like a mix between FFXI's SAM and FFXIV's ninjutsu. It stands to reason that they'll have some kind of AoE skill even if it's not their biggest strength.