If I understand your question you are asking if you should use hub centric (center balance) or lug centric (finger balance) balancing on your 5er wheels.
I would say it depends on the wheel and the hub. If the wheel manufacturer states that the wheels should be balanced hub centric then your wheels should slide snugly onto the center hubs on the trailer. If the wheels and hubs do not slide snugly onto the hub then you really only have the lug studs to center off of and therefore need to do a lug centric balance.
Clear as mud?