Eh, isn't Morrowind's combat much the same? The longer you hold down the mouse, the harder you hit.
It's not THAT: in Morrowind, the strongest attack (when you hold for several seconds) is comparable to the basic attack: 3 or 4 times stronger.
In Arx Fatalis, you cannot compare the strong attack with the weakest one.
Let's say in MW you strike for 3 damage with the weakest trust. So you score 9 or 12 with the strong attack.
In AF, you hit for 1 or no damage with the weakest trust but you strike for 25 if you hold the attack for longer.