The numbers simply don't add up for me. I take your points but I doubt mammoths were ever "easily exploited" -- ditto dire wolves, sabre-toothed cats, cave bears etc. Ground sloths maybe. I like your Larson cartoon BTW.
While Occam's Razor might indicate your conclusion, in this case there's simply not enough real evidence either way to convince me. I need a whole lot more data about how many hunters there were etc.
But mammoths existed for thousands of years, the Clovis people showed up, We have found Clovis points in mammoth butts, then we find no more mammoths.
Did the Clovis people cause or contribute to the extinction of the mammoth?
We will never know.
But there is an obvious pattern of humans showing up, and lots of mega-fauna going extinct.
The evidence of that is hard to deny.