TWCS and
Logitech 3D are both individual USB controllers.
So is just matter of goes to (modern) games controls and assign each one individually, all actual flight games recognized more than one control, some 4, some up to 8 or more, and don't give a #%&*$# for brands.
But if your flight game is from 90's and recognized only one controller, you can use Joystick Gremlin and combine both controllers in one virtual, so can assign both in these games. Joystick Gremlin need vJoy for this virtualization and this software is a bit PITA for install in some combination of computer+Windows+programs+user.