Law and Kidd are irrelevant anymore. After they fought yonkou and get huge L , I dont think Oda will bring those characters at some point again. Also there are so many matchup potential for them. There are SWORD , CROSS GUILD . If Dragon and Sabo will get huge fight , probably , this will be against world government not marines. Marines and World government is not same .
With this logic , after BB pirates arc , All SHs will be irrelevant except Luffy . Not buying it.