You can get 9 shots out of an SMG as well. That's probably not optimal use of ability points, but anyway, with 14 Dex, Adrenaline and two Rapid Muzzled 5mm Jaguars, you can get 7 bursts of 9 shots in one turn. That's effectively 60 shots potentially spread over 7 or more targets, versus a 7.62mm Muzzled Hornet or 8.6mm Rapid Muzzled Hornet which can fire 18 shots against 2 or more targets, depending on whether or not the bursts hit secondary targets. Obviously assault rifles have much, much more damage potential per burst with Concentrated Fire, but is that as useful as being able to spread your damage over many more targets?
I suppose range and accuracy is where it gets interesting, but I don't have any practical experience with SMG builds so I can hardly comment on that.