To objectively test all models the harness would need to be the same and ideally independent. Failing that, all three models should be tested in all three harnesses and the output verified on a model x harness level and on an overall aggregated model x all harnesses level.
Yes they do according to databricks -> https://www.databricks.com/blog/benchmarking-coding-agents-d...
That's why I find comparing models on benchmarks only gives the tendency. We should be comparing model x harness to have accurate metrics.
Testing each lab’s model in its own harness just tells us how well the lab has performed. For the model’s performance we need a control and the only way to get the control is to either test all models in all harnesses or all models in the same harness