Comparing camera performance with low light and action

In low light situations, what is a proper benchmarked way of comparing cameras capabilities? DPR has a studio comparison widget. And at high ISO, LX7 does not compare well against the G15 or RX100. But is that a fair comparison? Since in the same low light situation, isn't it also true that a camera with a wider lens might need a lower ISO setting to capture the same picture? So how do we evaluate cameras against each other in terms of how they would perform in the same situation (not at the same ISO which presumes all cameras require the same ISO in every situation)

Also, I was wondering how aperture size and sensor affects action photos and motion blur. Is a camera with a fast shutter speed the best way to capture action, and you just have to look for a camera with enough light exposure from a wide lens and a big enough sensor to be able to capture that brief amount of light coming in through a fast shutter? I'm trying to figure out conceptually how to approach evaluating cameras for capturing action.