If Ireland is fired the idea that Philbin will also be fired is a very real possibility since a new GM might want their own head coach. If Philbin is fired after just one season, even with a losing record, this franchise deserves all the negative attention and laughter we would get during the offseason.
Things look ugly right now, but firing Philbin and looking to replace Tannehill is not the way to go to try and fix things. New head coaches starting rookie quarterbacks usually have early struggles and growing pains, with some rare exceptions. Why can other teams be allowed to have those growing pains and the Dolphins can't? Starting completely over is not the way to go. If at the end of the year Ross decides Ireland is not the GM for the long term(I still think Ross is going to stick with him), you better hope that Ross lets Philbin pick the GM or that they promote from within.
Another complete startover(GM, head coach, QB) is just going to lead to more struggles and pain. You can't keep firing and replacing people after only one season, you can't build that way. If you want to fire and replace Ireland, fine, but make sure you are able to keep your head coach and quarterback in place.