The saddle joint is what was typically used in sash window and door construction. Rather than leave a little bit of short grain wood (as Tage Frid called it in the 1st book he published) which has very little strength, just go ahead and mill the mortise all the way through the end which vastly increases the glue area. This essentially creates a very long groove for a very long and wide mating tongue. Doweling it increases the racking strength. One of the issues here is modern glues. Yellow glues and the Titebond glues (1, 2, and 3) all seem to glue with hard, inflexible glue lines. Traditionally, from what I've read, glues were hide based glues which would stretch before they fractured. Hide glues are water soluble and have very short open times which make them hard to use. Which is why woodworkers have moved away from them. But from my experience with very old furniture they still outperform. Weldbond is one of the only modern glues that still has some stretch to it. It might work with that angled tenon approach but I wouldn't expect one of the other glues to survive that long. They tend to fracture over time as they get brittle. With the horizontal tenon a large portion of the force is straight downward on the wood at the bottom of the mortise. The rest of the force is torque which has to shear the fairly large glue line between the parts. But with the angled tenon there is a component of the force on the joint that is downward not against the wood of the mortise. So now the glue has to hold what the wood is holding in the other scenario.
Some consideration has to be given with what is my most likely method for success with what I have to work with and what my skill set is. Certainly a couple of dowels or so through the mortise and tenon assembly will help with that if you aren't certain that what you've done so far is good enough. There isn't always an absolute answer.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.
Last edited by Cherryville Chuck; 01-24-2019 at 02:36 AM.