I find it confusing trying to work out whether Ghostery stops the Google tracking cookies (esp. the ones associated when you sign in) or whether Google can still track your web browsing (see the websites where you've been and associate your google id with those visits.)
I'm running Firefox browser btw. Hope the question makes sense.
Short answer: It's a little more complicated than a simple "yes" or "no". But having Ghostery definitely helps.
Long answer: Google does a lot of tracking. Some of them cannot be stopped by anything short of not visiting it, because the tracking is based on IP address. There are people who do opt not to visit Google at all and use DuckDuckGo instead.
There is another category of tracking that is done independent of your login cookie, so as to track you regardless of whether you are logged in or not, regardless of you visit Google or its affiliated partners. Theoretically, Ghostery can take care of those good and proper.
But yes, there are yet another tracking category that is tied to your login and that's the very nature of being logged in. That's how it shows you your Gmail and Google Drive contents and knows you are you. Those cannot be stopped by Ghostery because doing so compromises functionality and you do not want to stop those. One thing about this type of tracking is that Google cannot use it on third-party websites, so even if Google used this type of tracking, it would effective within Google's own domains. And while I cannot say with certainty that Google uses this type of tracking within its own domain for additional monitoring, I know that Microsoft definitely does! (Within its own domains of course, but they are more extensive than Google's.)