Brilliant. Takes guts to call out VCs like this. Now, I don't think your 6-month time period is the right data point to measure if they are a zombie or not. There are a lot of different reasons why VCs take short investment breaks, and the 6-month period does not allow for that. I think 18 months is more in line, because it allows you to see more of the failed investments and results overall. A zombie VC should be defined with a ratio of failed (money lost) VS. successful (money gained) deals. If they have a lower than average ratio then we can say that their confidence (and the confidence of their bankers) is down, and they are operating in Zombie mode.
But I'm probably wrong, because I am a value investor.