The term “fastboot driver” is basically any driver that will recognise the phone in fastboot mode, and allow the fastboot(.exe) application to talk to it. (What it calls itself is mostly irrelevant) It sure sounds like there are multiple ones that would work. Best way to check, is to try and use fastboot. Not sure what the triangle is telling you, stopped using Windows 10 years ago.
e.g: (guessing how Windows will want it - assuming terminal is cd’d to the directory of fastboot)
./fastboot.exe devices
and
./fastboot.exe getvar product
Edit: and i’d not trust “The best drivers for your device are already installed”, but start by testing before trying to swap drivers.