On the 16SZ/18SZ you can freely assign any control to any stick, switch, dial or slider. I know F5J guys that use a slider for the throttle. Plus you can even change those assignments in a Condition (you have 8 conditions per model).
On my F5J planes I have the throttle on the flap stick during launch, then I flip a switch and I have flaps on the left stick. Amazing power and flexibility.