The problem with is that using this metric is not a direct comparison of charging rates/capability.
Example: The Model 3 is a smaller vehicle, and despite the fact they both have the same more efficient motors now, the S will likely always use more power per mile for locomotion. As such even if the S is upgraded to the same 250KW charge capability as the 3, it will always be inferior if rated on a miles added per minute basis.
If a small econo-BEV is efficient enough, it's possible that it's miles range addition at 150KW could be superior to an S at 200 or 250KW.
Simply put, miles-per-minute is a measure largely influenced by vehicle efficiency, not just charge rates.