Mumbai Rajdhani runs 1368 kms in flat surface, whereas Howrah Rajdhani runs 1225 kms in flat surface. many times 12951/52 has been overtaken by trains between MTJ & NDLS, so the comparison is baseless, NDLS MMCT route is not over saturated as NDLS-HWH route, NDLS-MGS part is 250% oversaturated. hence train controlling is tough.