I think its more a case that Dawes put out a very good touring bike that became the bench mark by which touring bikes are compared, a bit like the jaguar e-type being a bench mark against which sports cars are compared
unlike jaguar, dawes manage to update and keep the galaxy going.
each make does have its own way of laying out the geometry which can affect how the bikes feel and handle, for example, if trek favour long top tubes when building their bikes they'll get known for being race / time trial bikes or whatever discipline they are best suited to.