Complex sentence: Elliott felt that he was sidelined by the new leadership of the Australian Army this was most probably due to his outspokenness particularly in relation to these changes and indeed the war time records of some of those now being selected for the prime appointments.
Split into simpler sentences: Elliott felt that he was sidelined by the new leadership of the Australian Army. This was most probably due to his outspokenness, particularly in relation to these changes and indeed the war time records of some of those now being selected for the prime appointments.