To create some new threads and keep the JKD forum fresh..
Would training in european combat arts be furthering my own JKD more than the regular matrix of wing chun, muay thai, savate (i know european as well) etc. Maybe just continue with the FMA training?
The reason I ask this is that I was reading a book on German longsword training.
The authors differentiate between sword sports and sword combat. the importance of fitness training. Using simple movements over complex movements. It even states that one should train unarmed and dagger because there are in close technique with other weapons.
Int just seemed that the european weapons arts understood martial arts better than many asian arts in terms of real combat.
I think you'd be taking the JKD habit of investigating obscure things that will bring few benefits to new heights.
some more
FMA is largely WMA, based heavily on Spanish methods. Anyway, I recommend one simply study principles of movement and not worry about where it came from. Understand basic human fight or flight response and filter everything through the conditions which we live in NOW. That's the best we can do. 
sub