That may be, however I'm not looking for experiences when learning software engineering topics. Instead I want something that fits together with my existing kno

That may be, however I'm not looking for experiences when learning software engineering topics. Instead I want something that fits together with my existing knowledge framework and delivers significant benefits. Programming languages are table stakes and they compete for attention with the things which do matter in a project, like the social aspects and project management, team skills, development ecosystem and domain knowledge among others. Having for example deep knowledge the kernel would be more useful to me than all of the languages in your list combined.