You are having problems because the Clark does not allow assigning functions to switches
Most current controllers require a half stick movement for stuff, it is quite annoying honestly sometimes. However there are some controllers out there that allow functions to be assigned like the IBU3 and I think the TK60. For that my friend you may need some custom mixing...
You could set a switch to do something like Yaw=100% + Throttle =0% for the machine gun, but just assigning a switch to a specific function for the TK22 isn't possible without some clever mixing
