A friend of mine, Tom Homberger, who coaches a youth Sailing Team gave this analysis:
OK – I’ll take a shot. All sailing downwind.
GBR on Starboard tack has ROW over FRA & KIWI who are on Port tack (rule for vessels on opposite tacks).
FRA & KIWI???
Between these 2, FRA might be considered leeward vessel and have ROW over KIWI (rule for vessels of same tack). KIWI would need to give way by heading up.
Or – hard to tell but if FRA is overtaking KIWI boat from behind then KIWI is ‘boat ahead’ or ‘overtaken boat’ and would have ROW and FRA would need to give way (rule for same tack overtaking).
Generally ROW rules work well for keel boats, skiffs & dinghies. Not so much when zipping along at 45kts on a short ‘made for media’ course.
I remember the windsurf slalom racing in late 80’s/90’s basically threw out the rule book and it was every sailor for themselves. The tribe would settle disagreements in the parking lot afterwards. Kinda worked!