Arsenal have struck a new agreement that will amplify their ability to compete in the transfer market for years to come. It has been a relatively modest window for Arsenal so far, compared to last summer at least. Riccardo Calafiori has come to the Emirates from Bologna while David Raya’s loan move from Brentford has – as expected – been made permanent. Even if and when Mikel Merino’s move to Arsenal from Real Sociedad is complete, it will have still be a quiet window by the Premier League’s own stratospheric standards. Profit and Sustainability Rules (PSR) have had a concrete impact on spendi…