Ok I play at maximum difficulty and I took 1 hour to slain a Dragon that was fighting with a giand and I loved the battle , because I had to use a lot of tricks and get around them but with spriggans there is nothing I can do apart lowering the difficulty , its just impossible to beat them straight fowarding as they start with the damn ray that svcks all your energy unless you have a ton of cure spells and potions they are near impossible to beat ... I think are way overpowered compared to Dragons and Giants ...
Playing at Adept Difficulty they are hard but much easier than dragons or Giants. The problem is all Difficulty increases is enemy health or lowers the damage you do, and since Spriggans have the ability to heal almost all their life at least once when close to death, you get two extremely long health bars for the price of one.
The game was obviously only balanced for Adept.