Couldn't agree more. Exercise science background would be the most practical. I've covered the same ones listed and they provide basic, safe training, but without further application and branching into other methods the background could be regarded as probably the most 'unproductive' training methods.
It's a shame most personal trainers feel their course is enough and have stopped learning as soon as their piece of paper was handed to them. They walk around like moving toothpicks and look down upon everyone else. They see any sign of muscle as roids. Some come straight out of their associated courses and are content on using a fit ball and getting a person to stand on one leg. That's usually what many of them do. A lot of are toothpicks and some are even the fattest lazy slugs I've seen.
Best way is to gather as much knowledge as you can, apply it, gain experience and learn what works, and never stop learning.