Every part of your analysis is cherry-picked to maximise the effect of Son and/or minimise the effect of Kane. It doesn't make sense (except in the way you wanted it to). If Kane is the player under scrutiny, how does it make sense to only look at games where Son was involved? I might be stating the obvious here but Son isn't Kane. There's a sort of inherent assumption that "Son will be playing all the time so it doesn't matter what happens when he isn't". If you want to get rid of Kane because Son is apparently a viable replacement at CF, how are you accounting for Son's absences and the dire effect that would have on the team without Kane (see also: right now)? You're also introducing a false dichotomy between Kane and Son despite the fact that the team is easily at its best in attack when both are acting as a synergistic unit.
In tandem, it all looks like a ploy to keep losses off the record, like how the added constraints erase the losses to Colchester in which Son played as a sub and Bournemouth where Son played half the match before getting sent off (is his recent tendency to get red cards not his own fault now?). You're looking only at the last outcome of cup ties to exclude the fact that both of those FA Cup ties required replays (add an extra two draws to the results total) and that two of the CL matches resulted in losses (add two losses). There's at least two more dubious cases I can think of off the top of my head.
I can't be bothered to go through all of this in depth again but the way you've presented what is a mediocre record without Kane (not "without Kane and then only when Son is present but not when Son's done anything wrong") during that time period is similar to the way a corporation tells its shareholders about a bad year. It's disingenuous. And I'm completely ignoring my own analyses from the recent past that explain how Kane has been shafted by fate over the years because I've said enough already and I'm bored by the basic premises that a lot of people seem to bring to the debate. They can be found in this thread anyway.