I'm not talking about checking/changing every tool call, I don't even know what you mean by that to be honest. The question is about selecting the tool to use in a particular scenario.

The whole point of Jev/Kev is efficiency. If you can make decisions faster, cheaper, and more reliably that's the benefit. Even within the model architecture itself, you could use a classifier as a router within MoE to pick the expert that's likely to give the best outcome.