Then there is the wedged half dovetail, wedge....

Perhaps an engineer could answer this question, how much pulling load is actually applied to the post, exerting pressure the tie beam joint? And with these hydraulic pulling machine they test with, how much more pressure is applied to the joint that will be seen in the life of the structure at worst cast scenario? Is it like testing tire load ratings and putting a load on a tire to the point is bursts where we would see failure in broken springs, or bent things before the tire blows? I am presuming these test are performed to build number that will lead to specifics, a broken joint is not necessarily the end goal, more degrees of failure at given pounds of pressure.

Peg and wedges, a belt and suspender approach, I wear both, btw. The belt holds things and the suspenders keep my pants up when in use and when the zipper is run down for other purposes, a perk, I guess.

I can see times where just pegs could fail with relish blow out then there is not back up plan, a wedge adds a back up plan in times of need. Were the original builders adding a wedge for the future, or unforeseen needs, like shifting foundations and the such?