Translation of "Presumptuous" in Japanese

It's presumptuous to say that it's "production". Isn't it more processing?

生産て言うのもおこがましいな。処理くらいじゃないか。

It would be presumptuous to call myself his replacement, but I could offer some guidance.

代わりと言っては何ですが、・・・私が、いささか、ご指南いたしましょう。