I think this is a creative approach. I wonder how the success rates for that little RNN compare to the success rates of the primary LLM, especially for complex queries or complex tool calls. At some point you have to scale that network up large enough to get better results. Eventually you've come back around and you might as well use an LLM. I think a similar approach with potentially better results (depends on the application) could be accomplished by using that same dataset to finetune a small language model. It'd be interesting to see some success rate comparisons.