Well, that last comment does clarify things or narrows the contention, so that's helpful. You would have to go even further though to be convincing on that last sentence, something like, "...when the outer side of the tenon hole has a corresponding angle to the bearing side of the wedge inserted..." for example, and even then it's an up-hill argument. You wrote earlier the wedges are 1:8 a standard ratio of slope for a dovetail joint so I guess the hole that wedge fits also has a corresponding slope or something comparable for an equal dispersion of the pressure drawing the tenon in, otherwise I now understand the likelihood of blowout you fear.