Yep. I've seen operatives do it as well a few builds ago.
Snipers do have the highest single damaging ability for sure. What puts Merc/Commando burst right up there is that they both reduce the targets armor with their primary attack, but they can piggy back instant attacks on that attack and tracer missile hits so freaking hard. Once you have a full stack of heat signature on a target, (EACH MERC GETS THEIR OWN STACK, don't know if this actually stacks cumulatively or not, haven't tested it) a Merc can just fire off 1600-1800 damage tracer missiles every 1.5s or faster depending on haste. This is also in basic gear. That is both high DPS compared to pretty much everyone else, but it also has the potential for huge spikes by throwing instant attacks immediately after a tracer.
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