The best way to set the fans is to the temperature for where you can get the most cooling without the fans running all the time. I did this by using a base setting, then driving in conditions where my Mustang would heat up the most, i.e. traffic, stop lights, stop signs, etc. Once I got to where it would heat up enough to turn the fan on and at idle be able to cool it down enough to shut them off in the worst driving conditions is where I set them.
I know you have the SCT and from what I see there is not settings for multiple fan speeds, correct me if I'm wrong. My Predator has settings for low speed 1, low speed 2 and high speed fans. So for mine the settings ended up being low speed 1 on at 202, low speed 2 on at 204 and high speed on at 208. I then set high speed off at 206 and low speed off at 200. Now even setting in traffic with temps in the 90's my fans will kick on, go up to the low speed 1 & 2 then cool back down to the 200 and shut off. The hi speed has yet to kick on. Once I get back up to moving the temps actually drop back down into the 182-188 range and the fans never kick on while I'm driving.