The one on the throttle actually is the best choice for the thrusters. That one is nicely and conveniently placed, very good too use. When i try to use the one on the stick for that, i am way less precise. I guess it's something about the size of the stick and the angle my thumb is there at.There is one on the left side of the Joystick and another of the same type on the right side of the throttle, these have 4-way hat functions but also a push setting. On the throttle there are another two 4-way options these are the two silver/grey ones on the right side of the throttle
Edit: to really clarify, the analogue stick on the joystick is technically perfectly fine. But when you already fly the ship, move the stick, perhaps twist it, too, then at least for me it's hard to still use it precisely.