Potentiometer for adjusting sensitivity - value of resistance matters?

So I need a potentiometer as a type of calibrating tool. If the system is too fast, the potentiometer will reduce it, and vice versa. Question is, does it really matter if it's 100 ohms versus 1 million ohms? All that matters is the relation between the voltage divider static sensor and the potentiometer's value, correct?

100 ohms will draw quite a bit of current, i.e. places a heavy load on a sensor.

1 Mega ohms is not a good match for an Arduino analog input.

10k is a good trade off.