Early insights into the expected performance of the A14X Bionic suggest that it will be a true upgrade over the A12X Bionic, unlike the A12Z Bionic that graces the latest iPad Pro range. Comparing an ARM chip that is unlikely to make it into a laptop with a 45 W x86 processor is just as meaningless as ever, though.
https://www.notebookcheck.net/Early-insight-suggests-that-the-A14X-Bionic-will-be-a-powerhouse-but-comparing-it-to-the-Intel-Core-i9-9880H-is-wide-of-the-mark.488012.0.html
comparing A12X to Snapdragon 865 doesn't makes sense either because that's basically drawing a comparison between a phone with full fledged tablet with higher thermal output and power delivery. it's direct competitor are actually Snapdragon 8cx.