Well, my friend has appeared for both CAT and XAT exams. She filled the MBA admission form from XLRI knowing the difficulty level of XAT. XLRI is a prominent university that has high demands among the students hence, it isn’t easy to take admission here. If you clear CAT with good marks, there are high possibilities to clear XAT with good marks as well.
Considering the ‘average’ students who usually score average in academics, they have an equal chance to get admission. Moreover, I believe that besides passing or scoring good marks in the XAT or CAT, the admission of the students depends on other factors like knowledge, performance in GD-PI and total appearing candidates.