If only it were that simple. Unfortunately it's not. ARB rates required depend on spring and damper rates too. So you can get wierd results like that you describe.
Sounds like you may need a bit more front spring rate or maybe even front bump.
When I adjust sets I tend to work in 1 (defo not more than 2 or 3) clicks at a time.
Often, if I want less oversteer I will add 1 click of ARB, spring and front bump.
Also, your brake balance could be affecting things. Too much rear can make it snappy under braking, too much front and you can't get the nose in while trail braking.
Also, try messing about with the diff. Not enought pre-load or coast locking can also cause the problems you describe.