This is the real answer here. For the only alternatives you're forced to trust yet another party and with something like AV that basically equates to the third party having full control over your machine should they decide to do so. At least with Windows Defender you aren't adding another adversary although it seems pretty hypocritical to avoid American AV while still using an OS that the NSA can push updates to.

Get Windows Ten should have been an eye opener for everyone, vetting updates isn't anywhere close to good enough, if Microsoft is compelled to do so they can run whatever they want on your computer.