Not to be rude but like spend four seconds reading the post I made above yours. I literally give a run down of the alpha. And again it should be taken with a grain of salt because we're missing Azerite armor abilities that will modify specs.
Also you not having the correct legendaries doesn't make arms a bad spec. It makes the legendary system a punishing one, but nothing to do with the spec itself. Plenty of players with correct gear have minimal downtime with correct play.