Meaning the first best language depends on the job?

Of course :)

There are many jobs where the .Net/Java/Go triad would be in the top 3. I lump them together as typed languages that are mainstream, performant, have a GC and a featured library.

I'm at a java shop. All customer facing apps are in java. Our tools and glue code is mostly in python. Similar for data processing workflows

Yes that might demonstrate the point. Would Python be your second choice for the customer facing apps?

Unfortunately, might not be easy in practice. It took years of effort to pass some certifications and audits and I don't think adding another language could be recouped now