Complex sentence: Due to poor coordination, the armies of the Ava-led Confederation and Arakan were driven back by better organized Toungoo forces in April 1542, after which the Arakanese navy, which had already taken two key Irrawaddy delta ports, retreated.
Split into simpler sentences: Due to poor coordination, the armies of the Ava-led Confederation and Arakan were driven back by better organized Toungoo forces in April 1542. The Arakanese navy, which had already taken two key Irrawaddy delta ports, retreated.