Your sentence uses an ellipsis. The "underlying sentence" is:
- We consider Nigeria a developing country as we consider Angola a developing country.
Grammatically, do is considered a pro-verb in your original example, since it "stands in" for the verb or verb phrase (like a pronoun "stands in" for a noun). The verb phrase "consider ___ a developing country" is what was swallowed up as part of the ellipsis.
Can we use "with"?
No, it should be more obvious now, looking at the underlying sentence, that it wouldn't make sense grammatically to add with:
- We consider Nigeria a developing country as we (do)
with [consider] Angola [a developing country].
- We consider Nigeria a developing country as we (do) [consider]
with Angola [a developing country].
I think your example sounds awkward, but it's hard to pinpoint why.
It might have something to do with the fact that as usually allows inversion, but that doesn't work in your sentence.
It's also not clear to me what you meant with as. It doesn't sound like a comparison should.
You might want to look at some real world examples, like these ones from Wikipedia:
- They swam, but I didn't.
- He looks smart, and so do you.
- You fell asleep, and I did, too.