Use な to connect the て form and もんだ

Question

「ーーあの危機的状況を経て、全員生き残ってる。みんなの頑張りが、みんなの命を繋いだ。これ以上の結果は欲張りすぎってなもんだよ。……」

Why can we use な to connect the て form and もんだ? What is this grammar phenomenon? Can we just use すぎるもんだ?

Answer 1

It's a colloquial variant of これ以上の結果は欲張りすぎというものだよ.

• This (っ)てな is a corrupted version of という or というような. It sounds a little dialectal or shitamachi-ish to me (typically heard in rakugo performances).
  • What is な-particle doing in `ってなわけで`?
  • Meaning of てなわけで at the start of a sentence
  • How I should parse/translate てなことで at start of sentence?
• This もんだ is the same as ものだ, which you have already asked about.