There is. You should also be aware that you have to go to Sohaty with all the units he requires - this is one of the downsides of that quest - giving units one by one doesn't work.
Robbers are almost always guaranteed on debir, in the cave. Curvy Eyes usually sells some, so you can check him out before killing him. The building next to his hideout usually has them, but it's completely normal to get a sucky randomization and be left without Robbers in these places.
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