The order of levels matters
If you really want Divine Might and Divine Shield in NWN2, you can do it even if they don't fix the rules. What you have to do is take your Paladin levels at just the right times.
For the first case, I'll assume that--like the original NWN--you don't have to take the Paladin levels consecutively (no Paladin multiclassing restriction--at least, I think it's not present in NWN). If that is the case, make sure you level up your Paladin levels on levels where you get feats. It would look like this:
[sblock=Level Progression]Fighter 1
Fighter 2
Paladin 1
Paladin 2
Paladin 3
Paladin 4 (6th level, take either Divine Might or Divine Shield as your general feat)
Fighter 3
Fighter 4
Paladin 5 (9th level, take the other one as your general feat)[/sblock]
Assuming NWN2 follows core 3.5 closely, you might have to take your Paladin levels all consecutively. This would create a slightly different levelling scheme:
[sblock=Level Progression]Fighter 1
Fighter 2
Paladin 1
Paladin 2
Paladin 3
Paladin 4 (6th level, take either Divine Might or Divine Shield as your general feat)
Paladin 5
Paladin 6
Paladin 7 (9th level, take the other one)[/sblock]
In either case above, I'd recommend taking at least one more Paladin level than shown, just so you get the extra benefits (spellcasting, different skills, etc.) with no real cost (fighter feats are only given on even levels).
Hope that helps, and welcome to ENWorld!