that's not including their national guard force and how many soldiers they can commission in case of conflict
That is very small but considering the size of the country itself it seems reasonable. But in case of war it needs to be sheltered otherwise it will get swallowed easily.
Austria faces no threats from outside,they are a neutral country surrounded by NATO countries. The chances that Australia get attacked is near 0. Many people tend to forget that in case of full scale wars,large mobilizations would be decided and that the country's industrial base would participate in the war effort. Such as what happened during the WW1.
You never know what is going to happen in the future. Russia is getting crazy these days.