These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
From the main text: "It bears remembering that Gloucester did, in fact, order most of the killings he is portrayed as ordering, with the only clear exceptions being his wife and Clarence. The most infamous murder, however, is also the most disputed: that of his nephews, Edward V and Richard, Duke of York."
Gloucester did order most of the executions he is portrayed as ordering, and some historians think he didn't order enough of them. If he had only, for instance, executed Lord Stanley after the Buckingham-Richmond failed invasion of 1483, instead of pardoning him and - worse yet - handing Stanley's wife (Henry Tudor's mother) over to his custody instead of shutting her up in some forsaken convent for the rest of her life....
Gloucester had little or nothing to do with the death of Henry VI's son Edward, who was probably killed in the confused rout following the battle of Tewkesbury. And if anyone was responsible for ordering the death of Henry VI - if he was murdered, if he didn't die of a heart attack/stroke or commit suicide (both of which have been suggested by some serious historians) - it was Edward IV. Gloucester, in fact, was out of town chasing French invaders by the time the body was found, which gives him something of an alibi.