You mention Noun + 면 and Verb + (으)면, but they are actually almost the same thing.
Let's take the verb case.
- Verb + -(으)면 = "if (something) happens". It is the common conditional form of a verb (and adjectives).
* 서두르지 않으면 늦겠다 = We might be later if we don't hurry up.
* 비가 오면 천장에서 물이 새는 집이었다 = It was a house that leaked water from the ceiling if/when it rained.
Of all the verbs and adjectives, 이다 is a special one like "be" in English, as in "I am a student" (나는 햑생이다).
이다 always comes after a noun or pronoun (or a noun phrase), and it attaches to to it directly without a space.
This 'Noun + 이다' form also contracts by dropping 이 when it comes after a vowel-ending syllable:
* 나는 학생이다 vs 저것은 학교(이)다. I am a student / That is a school.
* 좋은 날이다 vs 좋은 날씨(이)다. It's a good day / It's nice now (weather).
* 이건 칼이다 vs 이건 가위(이)다. This is a knife / This is a pair of scissors.
So in many contexts, like the -다 endings above, -이다 might look like a single character ending.
That's what made you think -면 was coming after a noun. It is actually a contracted -이면, a -면 ending of 이다.
That is, 정도면 is actually 정도이면: 정도(quantity, degree, measure) + 이면(이다 in conditional form).
정도(이)다 means "is about this/such much, degree", i.e, it gives a rough estimate of something.
So 정도(이)면 is "if it's about this/that much, degree".
- 솔직히 우리정도면 괜찮지 않냐?
= 솔직히(to be honest) 우리(us) 정도면(if it's about that) 괜찮지(not bad) 않냐(isn't it)?
=> Honestly, isn't it okay [not bad] to be as good [cool, fine, etc.] as us? (literal)
=> Honestly, isn't it great/cool to be like us? (more natural)
=> Honestly, aren't we cool? (probably what's implied - but it's up to anybody's guess)
The phrase is not being specific about what it is talking about with 괜찮다.
괜찮다 usually suggests some positive quality rather than its original meaning of "not a problem/issue".