I already speak French, so I'll do this in English.
I know for a fact what some of the situation we have is, and it's very simple. My husband has been a schoolteacher all his life, so I have been able to be fully immersed. Also in my past life, I was a teacher, a facilitator, or whatever it is you want to call me, and I've had opportunities to work at that level. It goes like this: when BCTF gives you a certificate to teach, you're supposed to know and be able to teach everything, including chemistry, math, biology, and language.
Imagine my surprise when, while teaching French, I have Nancy Griffith-Zahner in my class, the woman who is going to be spearheading core French. I wasn't surprised really because that happens all the time. We don't get support from BCTF, and another reason that schools really do not like to go outside is that we don't want to disturb BCTF. This is not a slight on BCTF. I'm just saying that the expectation at that level is that you teach everything.
We have lost specialization in our classrooms, many years ago, and this is one of the reasons students are having problems in math and in languages. There is no secret.
That is my answer.