Actually it was more the speed and survival boosts that helped me with Fergus; doing more damage from the strength bonus (depending on the type of weapon) doesn't help much if you don't swing as often and miss more. There are more primary stats in BD than DD, so stat point distribution is not quite as simple. You will eventually be able to start ignoring strength (once you meet the requirements of the equipment you want to use) and constitution (as long as you have enough hit points that your characters can not be killed in a couple of hits by a strong opponent, you can compensate by using more healing potions or spells), in order to concentrate on intelligence. You should boost survival and speed at least somewhat at the beginning, and then as required later. Check out the math appendix of the strategy guide for a more detailed description.
