Trend for MBA education is like that only and if you take few of exams, your chances may vary so it is advisable to take all but that too depends on affordability and confidence level.
Perhaps of multiple exam trends for MBA education, it has given birth to ROI (Return on Investment) factor. Candidates too weigh and relate fee of B school to placement which B school might facilitate with corporate.
It is suggested that your appearing in most of MBA entrance exams will enhance the probability of chances and you might get options to choose B school of your choice.
Time is ripe to prepare and achieve mission admission MBA!