Having to make this decision, Franz found himself with no other choice. The Austrian army had just quelled a domestic rebellion, defeated the Kingdom of Sardinia, and even intervened in the affairs of the Papal State.
Now, he had hundreds of thousands of battle-hardened veterans at his disposal, and anyone with a bit of military knowledge understood how precious experienced soldiers were.
This meant that the Austrian Army's fighting capability was at its peak, not inferior to the military of any other nation of the era.
If he missed this window of opportunity, when the bloodied veterans had all retired, the fighting ability of the Austrian Army would gradually decline.
No matter how rigorous the training, it cannot compare to actual combat experience. A few victorious battles can build a formidable and confident fighting force.