Well in Algeria, France killed a good number of people. Their population was very low by that time a million may be. so the percentage of Death was higher. You would find dead people in every family.
But In Bengal the population were already 7 crore, So the percentage of Dead people was very low in 1971 and majority of the casualties were Hindus. If you ask any Hindu, I am sure they will have stories of their ordeal in 1971. Many Hindus who took refuge in India never returned.. Today Hindu Muslims may live side by side in urban area. But in 1971 it was easy to locate Hindu villages, towns and Roads. Also primary Job of Rajakar was to identity familiar Hindu locals.
You can believe me, It may not be 30,00,000 but not less than 3,00,000 either.
I understand what your problem is. Bangladeshis who are very vocal about 1971 also conceal Army atrocities that took place during CTG tribal insurgency.