I'm not familiar with either flash , but do they have a sensor on them for automatic flash exposure?
In which case , if your stood the same distance away and don't alter anything, then they would have the same output .
Is there a daily on it for setting ISO, aperture to be used , A for auto , M for manual setting ?
If so do the same test with both set to N for manual and set to their highest level , 1:1 .
Looking at the back of the 300 and WEXs website , there's plenty of buttons to alter the settings .
I suspect the power output settings have been altered .