Complex sentence: The largest Australian force deployed since the Second World War, although many of 1 ATF's officers and non-commissioned personnel had extensive operational service, it had been rapidly assembled and included many untried National Servicemen.
Split into simpler sentences: The largest Australian force deployed since the Second World War, it had been rapidly assembled. Although many of 1 ATF's officers and non-commissioned personnel had extensive operational experience, it included many untried National Servicemen.