In RMFRP/RMSS the category bonus is intended to handle the similar skill issue. Not sure where it is in the FRP book, but in RMSS it is 6.1 :
Skill Bonus =Skill Rank Bonus + Skill Category Rank Bonus + Stat Bonuses + Profession Bonus + Item Bonus + Special Bonuses, where for short sword with no ranks the skill rank bonus is -15(from table 2-2). The falchion ranks don't matter, it is the one-handed edged category ranks that help you out.