I'll start the speculation off.
Let's assume that Group 3 is ONLY about 2-hour strengthening. (The wording can be interpreted that way, although the 2-hour thing may only be one element of group 3).
Each group normally has 4 or 5 choices, each choice can have 5 levels with a max combination of 10 through the group. This would allow several different "original 2 hour" buffs you could apply, mix and match, various levels, to totally customize your 2 hour.
Let's try a couple out.
Ranger: Eagle Eye Shot
- Increase damage by 1 per level (EES is now effectively 5x hit). 5/5 would double the damage. Bah, make it 2 per level. We rngs deserve it.
- Increase accuracy in 5 steps up to guaranteed accurate.
- Increase range up to 2x current range over 5 steps
- Decrease enmity in 5 steps up to max of zero enmity
- Decrease recast timer by 20 mins, 10 mins per step thereafter for max 1 hour reduction.
Thief: Perfect Dodge
- Increase duration of effect 5 sec per step. Max would be 55 sec from current 30
- Add chance to dodge ranged attacks. 20% per step to max of 100%
- Add chance to dodge magical attacks. 20% per step to max of 100%
- Increase enmity when used so at level 5/5 it is equal to (unmerited) invincible
- Decrease recast timer by 20 mins, 10 mins per step thereafter for max 1 hour reduction.