Basic mistake with tech specs. The Israelis advertise the Derby-ER with a capability 80% to that of the Meteor and the Aim-120D, with a 160Km range, is only 50% as capable as the Derby ER. It has at least 50% more range (or greater) than the Astra Mk1 or RVV-SD. It's in the same class as the K-77M. It comes with a dual pulse motor, but I don't think you understand what that means, so forget about it. But I can dumb it down saying you can estimate its range to be anywhere between 150-200Km, closer to 200 than 150. The Derby ER's advertised range of 100Km is at medium altitude, and at that range Astra Mk1 is somewhere around 50Km, RVV-AE is somewhere around 35-40Km. In simple terms, it comes with a GaN based seeker, dual pulse motors and extremely modern navigation, and none of the missiles on offer to us are its match. Only the Meteor is superior due to its kinematic capabilities, but not the electronics. It's obvious when even the 160+Km Aim-120D is expected to be only half as capable as the Derby ER.
Second mistake, comparing the MICA's capabilities with another missile, when the main idea behind the MICA's design has less to do with the missile itself and more to do with the platform firing it. You can put a Meteor on an MKI, but you won't get the chance to use it against a MICA-equipped Rafale. MICA has been designed to kill stuff more effectively at closer ranges, which is why the smaller form factor compared to regular BVR missiles. It's built for a very different combat philosophy. But I doubt you are ever going to be allowed into seminars that will explain that.
Another thing you obviously do not know about the Russians is the downgrades. The actual range of the R-77-1 that the Russians use is over 130Km. But the export model, the RVV-SD, is basically a whole new missile, with new electronics, new motor, new warhead, new fuel, all inferior to the original, hence the inferior acceleration and inferior range. With the RVV-SD, all they did is match the Aim-120C5/7 because it's good enough. But the IAF can't afford good enough, they need the best that's available. And it's obvious Derby ER is just that. The Israelis and French do not downgrade weapons like the Russians do, which is why you get top quality from them and that's the reason why most of our acquisitions have moved away from Russia.
If Derby-ER is damn good as you said, why did not yet ordered by IAF or even integrated with MKI?
IAF could have purchased and integrated the same with MKI with its emergency purchasing power with US$400 per acquisition like we did in kargil scenerio with M2K.