I believe that Satoshi foresaw this very issue, and so avoided mining at all until well after the public announcement (if ever). Blocks 1-100+ were, I suspect, not mined by Satoshi.
Well, at least you agree that facts regarding the PoW of the first 100 blocks have a story to tell.
So, Satoshi announced Bitcoin, and waited without mining until people started mining...
But that does not agree with the fact that the INTERVALS between the first 20 blocks are spaced in time quite good. So network hashing power was stable.
People randomly starting and stopping mining would generate a completely different pattern of inter-block time intervals.