Perdiccas and Antigonus were very close to reunite the Alexandrine Empire
When Eumenes was victorious in Asia Minor , Perdiccas was murdered by own associates after failure to cross the Niles
When Antogonus was annexing Caria , his son , Demetrius was defeated at Battle of Gaza and Seleucus robbed him of the Babylon and eastern satrapies .
Soon after Seleucus defeated Lysimachus , he was assassinated . ( However , at the age of 77 , his hunger for further wars and expansion were doubtful )
Unexpected turns of events and shifting alliances to prevent anyone to emerge being supreme led to the failure of Diadochi to resurrect the Empire .
After all , they were all such capable generals and statemen that everyone of them had the ambition of succeeding Alexander and continue his legacy .
However none was first among equals themselves after Alexander the Great .