Arsenal are on course to smash a £173m club-record thanks in part to their latest high-profile commercial deal. The Gunners have fallen behind the so-called Big Six in terms of commercial income in recent years, with their revenue from sponsorship and merchandise now approximately half of Man City’s total. But the Gunners’ brand is, according to the latest analysis, worth £840m, which is the fourth-highest in the Premier League and seventh in world football. The problem they face is how to monetise their brand and their overseas following in a crowded marketplace. One are in which they have ha…