This figure of 3000 for just International Management seems difficult to believe. It may be the number combining all the management courses offered by UCL. For reference, the year before there were roughly a total of 3000 applications for the IMB and Mgt Science combined
As a sanity check, the claimed figure of 3K applications for International Management at UCL is more than 3x the volume of applications that the same course at KCL usually attracts every year. KCL Business School is ranked higher than UCL's. Granted KCL's requirements for IM are more stringent than UCL ( higher A level grades plus a GCSE foreign language grade of 6+) but it wouldn't explain the huge disparity in application volume IMO. My best guess is that the figure provided is the combined figure across management courses and the max IM volume is likely to be 500-1000. In any case, the actual stats should be out before the applications for the next cycle start up so we will all know.