Placed turrets almost never headshot so you don't really get to use that bonus and only the handheld turret dismembers, not the placed ones. Int Headshot bonus and dismemberment bonus effectively only applies to Stun Baton. But consider what I'm saying about how much Junk Turret Ammo I'm going through for a horde. 3,000 ammo for Day 20 (plus AK rounds plus shotgun rounds). Even if I placed 10 additional turrets to my main 2 that's 500 of the 5,400+ rounds I'm expecting to use on Day 26 and they are shot from turret with low to no mods and prolly lower quality.
Also, with that sort of kiting scheme it'd almost certainly compromise their directed entrance to my base. Right now I've got 3 sides heavily fortified with double layer walls and an open door towards that front that leads into a small room of fricken death and gore. No mazing, just thick walls with one entrance and alot of guns trained on it and electric fences

. Because turret effective range is about 5 blocks. At 7ish blocks they are missing noticeably more and already suffer -15% damage from range falloff and that only gets worse the further out you go. Even Pistol has full damage until like 12 blocks.
Having kiting areas means creating alot of potential weakpoints and potentially borking their AI. That's not much of an issue if you're playing with weapons suited to that or with multiple people like you are where people can react and clear, but if the kiting derps out their AI and they break through in another direction I'm utterly hosed.
Because turrets are my spec'd weapon I don't have near as much flexibility with build types. Their limited range and limited firing arc is just too much of a limitation. You need to be 5 blocks up minimum to shoot from above (and I've had zombies break bars and scale that even by standing on each other's heads). That's already past their effective range.
If things go south I'd be Benny Hilling it around my turrets and eve if that ends up working I personally consider that defeat. The point is for my base to stand against the tides. I'll go down fighting and eat my death if the base is non-salvagably compromised. I do plane on having a retreat to the second floor eventually for a second killing room, but that's for later later

.