Another possible opton would be not to create a war bow class in the new organization and any war bows wishing to compete would simply compete as unlimited draw weight english long bows shooting at a specified grains per pound, somehwere between 7 and 10 grains per pound is what we are discussing.
There yah go. That sounds reasonable.
If, for example, you're shooting a 100# EWB, and you specify 10 grains per pound arrow weight, that would be a 65 gram arrow. Very reasonable. That's very close to a Livery spec arrow, currently being used in the warbow societies now. This philosophy would level the playing field a bit more, as more draw weight would require a heavier arrow.
Would there be requirements for fletching and head sizes, etc? Without the heavy heads and long fletchings, you could certainly get much more distance.
With a current WBS livery spec arrow and a 100# bow, I can get 200 yards on a good day. I think with more of a "flight" arrow (minimal fletching, barrel tapered, light head, etc.), you could get much more... likely closer to 300 yards maybe.