Not only that, but unlike turrets Tesla are tall and can get in the way of shots unless you put them fully out of the firing lanes of the humans.
Also, the coordinated catching of barbs should ONLY be used when going after the goons has been settled out as a pretty much impossible task, which is rare. In the normal scenario, the team SHOULD be killing the goon in less than three seconds as soon as it shows, and rifles make that more than possible.
Another thing is that, assuming anything around 100 build points and the aliens have a relatively high number of larger classes, you should never have any defenses around choke points unless it's tied in with your main base (yes, this means nothing around the choke points in the ATCS human base). Humans would be required to cover pretty much every choke point, because it would only take one getting killed for an opening to let aliens stream in and kill the main base, easily. This uneven spread of firepower and requirement for extra defense can also be devastating on the humans' offensive capabilities.