Nope, if he got to that level, he'll know that the only way to really know it is testing.
He may still ask why one is slower than the other (if it is, I don't know that), but that's a completely different question that in most contexts will get a nice answer.
Suppose, for a moment, that our hero is seeing this situation for the first time and doesn't know what the alternatives are.
Tests that don't cover the best option can't possibly identify the best option. So if you want to do a really good test, going somewhere to ask, "What else should I try?" is hardly an asinine course of action. On the contrary, if our hero is new to this stuff, or is new to the platform in question, or anything like that, then asking others for advice should probably qualify as due diligence.
He may still ask why one is slower than the other (if it is, I don't know that), but that's a completely different question that in most contexts will get a nice answer.