Modern vehicles use helical gears and synchromesh equipment during the gearboxes, that synchronize the rotation of gears which might be about to mesh. This eradicates clashing from the gears and would make equipment shifting a lot easier. The Doggy clutch slides on the leading shaft to rotate with it. https://jeffreyobjtd.ampedpages.com/not-known-factual-statements-about-gearbox-60774667