1. Michael Saylor does not personally own these Bitcoin.
2. BlackRock does not own these Bitcoin either.
The shares of both are much lower than you have portrayed, and your topic is therefore very flawed. Each of them are buying coins for any number of people and entities that are investing in Saylor's company or BlackRock's ETF.
Therefore, Satoshi has significantly more Bitcoin than what these two examples actually own. However, satoshi is gone and will have no influence on the market. I would not give you any merit for this thread because it is very flawed.
I agree on this. Blackrock and MSTR don't own any Bitcoin personally; they're merely intermediaries for individuals or institutions, so they won't have much influence. Meanwhile, Satoshi is a form of personal ownership that we don't know whether he'll use or not, because that's his right, and so far, it seems his Bitcoin will never be used.
And honestly, we don't need to compare them, although the OP has a fear of them influencing the market.