「客先提示仕様」は、

specifications instructed by customers

ではなく、

specifications stipulated by customers

または

specifications for which customers have given instructions

です。

「客先等級」は、

customer requested classification

ではなく、

classification stipulated by the customer

です。

「40%の世界シェアをとる製品を6個設定いたしました。」という一文を英訳するなら、

We have stipulated a total of six products with which we expect to secure a 40% share of global markets.

または

We have settled on a total of six products with which we expect to secure a 40% share of global markets.

が妥当でしょう。