If the Kyndas were the closest units then the JMSDF might have been able to split their resources and take out two rather one

I do not pretend to be an expert on skimmers, but I think that you miss a fundamental difference between 80s era Sea Sparrow and Evolved Sea Sparrow. The latter is a capable system fitted alongside (a variety of) illuminators which can do clever time -sharing tricks. The former was/is little better than useless.