Of course! Also, I figured I'd respond to your private note here in interest of not having my message split up in 200 character increments.

I don’t think it’s always going to be a direct correlation between the proficiency and nativity, because I know plenty of native English speakers who don’t have a very good grasp on writing or basic grammatical conventions. But I’d still stand by what I said going off of my own experience and the experience of my friends.

Spanish (my second language) is a simpler language than English that follows its own rules more consistently. It doesn’t constantly defy itself and make people wade through nearly as many strange rules. But even though Spanish is simpler in almost every regard, I have a harder time speaking Spanish than I do English, and it’s likely to remain that way. Most of that, for me, comes down to lack of immersion in the language.

It’s certainly a pattern I’ve seen in others’ writing, too. There are things I know to do in my own writing and speaking that I don’t have conscious awareness of, but just through immersion in the language/country have developed a gradual sense for.

I didn’t consciously know why the word “advice” was incorrect to use in that initial context (sorts of advice is a good fix, btw). I just know the way in which I've always heard that word used throughout my life. It’s just the sort of error that, especially as a native English speaker, I’m more attune to catching. Similarly, I subconsciously understand that adjectives need to be put into certain orders when stacked. You can say the “big red car” but never the “red big car.” Why, I’m not sure. It just feels viscerally wrong. And even my friends without a great grasp of the language would know to follow that rule, regardless of whether they know why. I attribute that to immersion, too. It's another example of something that’s easier to grasp when English is just the language you grew up with and know no different.

I’ve experienced similar situations while traveling abroad, too, where customs are different and i’m the one unfamiliar to them. There’s no reason non-native speakers of a language can’t surpass native speakers, but I don’t think it’s offensive to say that, on average, it will be a greater challenge than learning a language from birth and being constantly immersed in it.