Hello,
1) There are 2 custom tabs already available for your products + 1 custom tab individual for every product http://prntscr.com/q5hkyl Is it not enough for you?
2) If you still need more tab then add priority to your filter params, for example
add_filter( 'woocommerce_product_tabs', 'woo_new_product_tab', 99 );
Regards