England fly-half Zoe Harrison says the introduction of smaller balls for this autumn's WXV Global Series is "the worst decision someone has ever made". Size 4.5 balls - about 3% smaller, but the same weight as a regulation size five - will be used for the tournament in September and October. World Rugby held a trial for female players on the top-tier Sevens circuit in November and announced last month the smaller balls would also be used by the world's best 15-a-side players in the upcoming WXV. England will face Canada, who they beat in last year's Rugby World Cup final, three times as part of the new showcase for women's Test rugby. The Red Roses also have home fixtures against Australia and New Zealand during an eight-week international window. "It's the worst decision that someone has ever made," Harrison told BBC Sport, explaining she only learned about the trial when asked about it by journalists. "I've not kicked any less than a size five since I was the age of 14.…