He is worth a hundred people so I have no worries.
He is as good as a hundred people so we have nothing to worry about now.
ここでは「百人力」を
worth a hundred people
as good as a hundred people
としました。
1) He is worth a hundred people so I have no worries now.
「彼は百人力だから心配はないよ。」
2) He is as good as a hundred people so we have nothing to worry about now.
「彼は百人力だから、何も心配することはないよ。」
「もう安心ですね」は
I have no worried now.
We have nothing to worry about now.
と言うのが自然で良いかなと思います。
Having him join us is like having a hundred other people.
「彼が加わるということは、100人力だね。」
のように言っても良いです。
ご参考になれば幸いです！
日本 
