We almost won the war before India won. Before India came , East Bengal Regiment was using their own weapons that are Pakistani weapons.You are right. It was bangladeshi bombers, bangladeshi tanks, bangladeshi artillery and bangladeshi aircraft carrier fighting the war
Ziaur Rahman looted Pakistani weapon supply and distributed into freedom fighters.
There were also other weapons too from cantonment.
India showed tank ,but if you study the geography of Bangladesh, tanks are useless in most of places.
Our soil is soft and not good for large scale tank battle.
Aircraft carrier later came but that was not necessary. It was show off! Indian naval blockade wasn't necessary to win our warfare.
Pakistan army from former west Pakistan was not familiar with the land of East Pakistan , so there was no reason for them to win the unknown land where civilians under their Eastern command Bengali soldiers Rebelled!