Mercedes have been bringing upgrades to their W15 car in recent races as they try to close the gap on the top three teams. The problem is that those ahead have been doing the same. The Silver Arrows have introduced the year’s first significant set of developments over the last two races in Miami and Emilia Romagna. But there hasn’t been any immediate upturn in results. They’ve collected only 26 points across the two events, with both drivers stuck between sixth and eighth. Indeed, Mercedes finds itself in something of a no man’s land at the moment between the frontrunners and the upper midfiel…