I have to disagree that different styles conflict with each other and that they are ALL complete styles. Complete in what sense? Does every style available today provide training in all ranges of fighting? No. If all styles where complete in the sense that they did train for all ranges of fighting then they would compliment each other.
The fact that today several schools are teaching a combination of systems brought together to cover the "gaps" should tell you that many arts are complimentary regardless of their lines of attack/defense. It is possible to study a "hard style" and a "soft style" together. It's the way you train that makes the difference.
I do feel someone should have a good understanding of one primary art before seeking out additional arts if only for the purpose of having a reference point. In the end fighting is fighting, the mechanics are the same. Different styles only provide you with a different means to getting there. When people mention Japanese/Okinawan karate as being impractical because it's too rigid or for whatever other reason, many fail to realize that the way you are taught isn't always the way you fight. This does tend to be a problem because some will argue that it is. The reason i say this is because at one point you must learn the basic mechanics of the techniques. Once they are learned you need to learn to flow through the technique then learn to apply it to resistance. Unfortunately a lot of practitioners and even worse, teachers, have lost sight of this and believe they are going to be effective in a fight by doing one step sparring or applying techniques they have never practiced against a resisting opponent. What’s the point? It doesn't matter if you study tae kwon do, shotokan or any other striking art the end result should be the same with proper training. Various forms of kempo/kenpo cover the various ranges of fighting just as the bujinkan does. They both incorporate various methods you would consider "contradictory" to each other, but when properly trained and understood they compliment each other.
I've trained in several arts over the last 10 years for two reasons. The first is due to my job i wasn't in on place for more than a month and had to train with whom ever i could regardless of style. The second reason was i wanted to have a better understanding of the various arts available and compare them. I feel i've grown more as a martial artist in these last ten years because of this versatility than if i stayed with only one style.
You mentioned you studied shotokan previously and now take JKD. Isn't JKD founded on the basis of several arts/fighting styles that Bruce trained and took what he felt was effective for him?