[FotoPlasma]

Jon's description is very good. I don't have anything to add, in that regard, but just as a precedent, teams have been making drivetrains that shift gears for a good while, at this point. A lot of them have done this by jamming one set of gears directly into another, and for the most part this has worked well, to my knowledge

If you're worried about wear in a dog mechanism (assuming that you're using (a) pneumatic actuator(s) to shift), you can adjust the force which the actuator exerts, and thereby reduce the force which would cause the wear, in the first place. However, if you decide to construct this mechanism, I'm almost certain that the pressure of the pneumatics system will be a fairly minor consideration. As long as you don't use a 2" bore actuator, I'm pretty sure the shear strength of gear steel will be more than adequate.