There are always trade-offs in the game that will tend to impact you more in the early, middle or late game. To me the early game trade-off of having more spell casters is more easily overcome; you can get bows and bow skill for everyone right off the bat and get past the very early stages that way. I might go with AACS because the various fire spells can be extremely useful in the early and mid game, but any of the parties mentioned are ok. The first level promotion quests for cleric and sorcerer are very easy and can be done early on. The initial Archer promotion is not quite so easy but not all that tough either with the right strategy and once done, the second promotion is almost instantaneous. I also agree about druids. I recently tried a 4 druid game and really didn't care for it that much and gave up. It takes a long time to get that many magic skills to a useful level and in the meantime you're really struggling.
And in regard to light and dark - one more big advantage is that all of the protective and enhancement spells can be done with three spells from light and dark. Also you can master both of them at level 4. That does take some work, but it's doable.
