They would need a model built on top of the submitted models to weight or select which specific trading signals to act on. A plausible model might be walkforwar

They would need a model built on top of the submitted models to weight or select which specific trading signals to act on. A plausible model might be walkforward testing on out of sample data, or as simple as trailing performance in live trading, or both. Still, with a large set of models, you won't be able to get around multiple comparisons problem entirely. That doesn't matter though because you only a need small amount of good signal to be profitable in the money management biz. The larger issue is whether the aggregate signal quality is high enough to be able to pay for development and trading costs.