Right. So when evolutionists say that evolution occurs by the process of random variation and selection, the claim, at least as originally vetted, is that, while the variation step is uniformly (sorry about the original terminology) distributed, after the selection step, the distribution is gaussian, with a central tendency toward those individuals whose attributes give them the best chances of survival. This is the invisible sculping blade with which evolution "designs" species as the blade changes shape over time. If you want to argue against the evolutionary story, this is what you need to attack. Attacking "chance", as if uniform distribution were the story is a strawman attack.
Do these chaps have anywhere even close to a good enough view of "macro" evolution to back up this kind of claim? They're saying they believe this is what happened, now can they back up this claim with the observation of the bulk of the "evolved" progression of species? Or is this a procrustean bed into which all scenarios of "evolution" must be forced?