Only Edward II (Marlowe) was not printed anonymously. It has frequently been claimed that Edward III was at least partly written by William Shakespeare, a view that Shakespeare scholars have increasingly endorsed.
→Edward I (attributed to Peele ? ) 1593
→Edward II (Marlowe) 1594
→Edward III (attributed toShakespeare?) 1596 (not included in The First Folio)
→Edward IV (attributed to Heywood ?) 1599
For Edward III Shakespeare scholars have increasingly endorsed that it was at least partly written by William Shakespeare. It contains several gibes at Scotland and the Scottish People. This could explain why the play was not included in the First Folio of Shakespeare's works, which was published after the Scottish King James had succeeded to the English throne in 1603
Conclusion: It seems neither realistic nor conceivable that within a few years 4 "King Edward (I- IV)" historical royal dramas were composed in London in a similar diction and fashion by 4 dramatists with no established evidence of a personal connection?
Why there has never been any credible attempt, to develop a consistent theory or explanatory hypothesis for this strange observation by academic Shakespeare experts?