It is not a strawman argument. It is an argument given to understand the purpose of such studies.
What do you achieve by quantifying the amount of money that was stolen?
What is your purpose?
Is it just for a couple of sentences in history books?
Is it just that you can feel good about yourself?
Is it just that you are able to condemn the British for what they did in the past if something does not go well in the present?
If someone stole something from my house, I would want to know what it was.
Not because it could be written in some police report and end up in their archive,
but because I would have wanted it back.
If forms the foundation for future negotiations. Hard data and Facts, not youtube debates.
Let's say when we want to replace UK as the next permanent member of the UN.
Will this be sufficient ? not, but it will play its role in swinging global opinion.
You are right that Zamindars were the rulers of most Indians and that they predate the East India Company and British India.
And yes, most Indians probably did not know who was actually ruling them, because of low literacy rates and lack of modern media and technology.
But even so, why should it matter what the colour of the skin of your oppressor is?
Why should you not fight against oppressors of you own colour?
How does having the same colour make oppression less of problem?
Because Hindus always fought against oppressors who spoke persian and prayed different and looked different and destroyed his school, universities and temples.
And to fight them, they banded together with those who spoke his samge language, looked like him and prayed to his god.
The Islamic invaders used the same system of having Hindus opress the other Hindus to keep their kingdom stable. EIC only took up from where they left off.
In a land where resources, opportunities, education, water, food and self respect became rare, people fought among themselves for survival, rather than figure out the big picture about who to fight. That needs a system and when the british put the system of english education in place, that too happen.
Hindus were already used to living as second class citizens under 600 years of islamic rule and most of their fight had been taken out of them till the british came. In fact, initially the british was looked upon as the saviors in Bengal and the current day durga pooja celebrations is the extension of the celebration that took place when the british first freed Bengal from Islamic rule.
It's only when leaders like the Sikh gurus or Shivaji came, the hindus banded together to fight the outsiders. Even then , most times they were defeated by infighting rather than the enemy themselves. That infightin was due to a lack of social consciousness missing and that was missing because all our schools and universities were destroyed.
Anyway this is not a simple question to answer. There are layers within layers which has to been seen, to understand the full picture.