I think it is unlikely that Satoshi mined with 58 computers.

The nonces 0 through 58 appeared in blocks more frequently than the rest possible nonces, so the range of nonces is 59, not 58. However nonce values 10 through 18 have a "normal" frequency. This might lead someone to expect that satoshi might have 50 computers mining in bitcoin's early days.

I think it is probably more likely that satoshi was intending to use 6 computers, the second computer broke (or otherwise was unable to mine), so he ended up using 5 computers to mine. If this is true, he may have configured 6th of the remaining computers to mine on nonce values 19 instead of 59 before realizing that the specific nonce values do not matter, and wont have an impact on the chances of any computer finding a block.

There is evidence that satoshi may have not mined for as much as 5 minutes following when a block was broadcast, and if true, he may have not immediately started utilizing all of his mining equipment immediately after the 5-minute timer expired.

Obviously, it is not clear these blocks were actually mined by satoshi, although I think it is more likely than not to be the case.