Nah, half the fun of tabletops are the thought-provoking discussions. There's nothing wrong with argument, especially if it motivates you and others to learn (and being right is one of the best motivators, heh). Arrows we can probably find, same with bows, whenever we capture a ship with armed enemies on it. It's usable lengths of wood that are the problem; you need specific sections of trees with the right properties, grain alignment, &c., and it's going to be unlikely for a random plank or railing to possess the right qualities for a good bow -- though you could probably make any number of crappy ones, and DnD rules don't really differentiate much in that direction.
Besides shortbows are 30gp and rapiers are 20gp, so even if Lora can't argue someone down, it's not like we don't have enough spare plain rapiers to trade for one -- the number one rule of loot is making sure that it's distributed effectively, after all; the better equipped each member of the party is, the more likely we are to avoid a TPK. Lora's essentially following the same sort of rule in-character, considering that she's CN (which in this case translates to selfish) and intelligent (which in turn means enlightened self interest), which then means that her first and foremost interest is in the safety of her own skin, which is best ensured by having those around her also be better armed and protected. It's also helping her get in good with a healer.
Selfish characters are so much fun to RP, especially when they're not stupid ones that just steal everything they can and screw over their friends meatshields for short-term gains. It's one side of the coin of 'doing the right thing for the wrong reason'; the other is being slavishly selfless because it's "good"/the law/whatever. ^^