There were around forty people on the company's payroll, but they were all trying to obtain information on each other.
こんにちは。
ご質問ありがとうございます。
"There were around forty people on the company's payroll,"＝「会社の従業員は40人ほどいた。」
"but they were all trying to obtain information on each other."＝「だが、彼ら全員、互いの情報を手に入れようとしていた。」
ご参考になると幸いです。
There were about 40 people on the payroll, but we were always probing into each other's information.
「会社の従業員数は40人程だったが互いの情報を探りあってた」は英語で「There were about 40 people on the payroll, but we were always probing into each other's information」と言います。
There were about 40 people on the payroll は「従業員数は40人程」を意味します。ここで "on the payroll" は「給与名簿に載っている」を指し、雇用されていることを表現します。
But we were always probing into each other's information は「互いの情報を探りあってた」という状況を示しています。「probe into」は「探り出す、調査する」という意味を持ちます。
アメリカ合衆国 
