Austria wasn't dismembered by the treaty, it had dismembered itself already due to lack of any popular support or redeeming value.
If anything, Austria (modern definition of) was artificially created by that treaty - the point being prevention of reunification of the German-speaking rump with Germany. There is the obvious issue of the German speaking parts of Bohemia, I suppose.
Actually Austria got Burgernland from Hungary, so they also gained territory.
The treaty shouldn't have given Sudetenland to Czechoslovakia and Southern Tirol to Italy, but the vast majority of the German speaking areas in the Hapsburg monarchy remained in the new Austrian state.
Especially the incorporation of Sudetenland in a Slavic state was unfair and foolish. It was fairly obvious that it would lead to trouble. As a minimum the area should have had a high level of autonomy.
Austria should also have been allowed to join Germany.
Unfair, but not as brutal as Trianon. Not more unfair, than could be expected after the loss of a major war. But none the less:
Stupid.
I actually think stupid vs. sensible is a more relevant criteria than fairness, when it comes to Peace Treaties.