I'd put the count at 2¾: Blink counts for ½ since it's an ex-fork of WebKit. While a lot of the new feature development of the two are independent of each other, they still largely share a lot of the same architecture, which means there's going to be correlation in things like ease of implementation. The extra ¼ comes from Servo, which ends up having the opposite edge of the dichotomy from Gecko; it's effectively a ground-up re-implementation of the layout engine stack, so its internal architecture is quite different from everybody else, but it's goal isn't to drive new feature development in web standards.

Microsoft will use Blink not WebKit. Teams and VSCode are already Electron apps.

Right, the point being made is that Webkit/Safari are often the slowest of the bunch which is fine when you have three others but now each browser effectively has veto power and the expectation is that Webkit will wield it often.

It's saying "oh no, now Webkit can block things", not "oh no, we don't have enough strong implementations"