Zoro fights the 2nd strongest who is usually, coincidentially, also a swordsman. If Sanji fights a dude who uses a sword as well there is no problem. Even more when it is just a secondary weapon at best like in this case with Queen. Then of course this is a first or almost, even if for classic pirates it should be a classic Oda can not fill every crew top spots with "swordsman". There are just a few excpetions like with Roger crew (basically all the top 3 were blade users. sword, sword and 2 axes).