Well, the Royal thorns are always there on the start island. I think they are supposed to be there. The number you get varies, but I have never seen less than 3 or more than 5. As for recruiter Norbu, the units in the camp vary. I have seen knights, paladins, bowmen, swordsmen... It depends. So I guess if someone wants a decent tank early on, saving the game right at the start and going over to the Scarlet Wind island to check what's in the camp doesn't hurt at all - oh, and while you're at it, you can check the tower in the graveyard and see if there are some Archmagi there. Archmagi + Paladins = easy no-loss victories early on
That is especially useful if you're trying to beat the game with as few losses as possible or you're going for the leadership upgrade medals quickly (like in the first 50 battles). Generally, if you get enough leadership and make a dash to the camp and then to the tower you can get a nice amount of strong units that will shrug off most the enemy attacks in the early battles.
Still, I think this counts the most on Impossible
The other difficulties will present easier going.