I agree to some point, but there was a lot thing with these state which made a new war unavoideble.
1: To weak Austria, a Austria as weak as in OTL "could" only end up as part of Germany.
2: The feeling of betrayel by the fact that it "seemed" Germans was the only people with no right to National Selfdetermination.
3: The fact that many of the borders was rather arbitary
4: The creation of New Multiethnic states dominated by a single nationality (Poland and Yugoslavia primary, Czechoslovakia secondary)
Solutions
1: A stronger multiethnic Austria with German South Tyrol, Slovenia and Fiume.
2: Drop the whole National Selfdetermination retoric.
3: Adopt some border which make both economical and political sense, give Germany West Prussia (or give Poland East Prussia or even the whole of Germany east of the Oder, even through that could really backfire) and let Slovakia stay Hungarian
4: There're really no soulution to this one except the same one as in Nr. 2.