Router models exist, and do something like what you describe. They run one model to make a routing decision, and then feed the request to a matching model, and

Router models exist, and do something like what you describe. They run one model to make a routing decision, and then feed the request to a matching model, and return its result. They're not popular, because they add latency, cost, and variance/nondeterminism. This is all hearsay, mind you.