again...it all depends.
I used another bar much lower in CO than usual, and this morning went back to a bar that is 80% CO and my hair is better than it's been in a few weeks.
For me, personally, with fine hair, all that low cleansing and high conditioning just leaves me an unhappy greaseball, where a SF CO bar (with a little castor and olive) and a vinegar rinse leave me with clean, shiny hair that can actually move.
If a standard bar isn't working as advertised, there's nothing at all wrong with trying different things.
I agree though, if it's matting because of the soap, try either a stronger citric acid rinse, a vinegar rinse, or a different acid (lemon juice, different type of vinegar) - I can't comb mine if the acid rinse isn't done, and citric acid was weird on my hair.
Do you have a list of the Trader Joe bar ingredients? Was it soap or syndet?