What is the difference from Bitcoin being solo mined and dash instamined? You dont even know who is Satoshi!
Here is the birth of DASH https://dashtalk.org/threads/the-birth-of-darkcoin.162/  nothing hidden, all transparent.

BTC was never solomined. There are well known people who mined at or near the very beginning who showed up later with a large amount of coins, plus a number of well known people whose coin holdings are less well known but clearly were also mining. Since there were no exchanges and little to no trading, mining would have been the only way to get them. Those are only the well-known ones, too. There were certainly other unkown people mining who were just more private about it ever since. As you said, satoshi is reported to have mined a million coins, but 2.5 million were mined in the first year, so clearly other people were mining too.

LTC was instamined, but as I said only about 1% of the current supply. If you are trying to argue that is in any way similar to a 33% instamine you are either being dishonest or are just very confused. I'm not sure which.