These rules aren’t current anymore and frankly, have never been accurate.
Your Zeek speed depends on the traffic you have, if you have some elephant flows (and how you deal with them), scripts you run, etc. I remember pushing between 5-10Gbit/sec through a server with 24 cores (not threads), with room to spare.
You will also need memory, and depending on scripts you intend to write, that might be quite a lot. We run with 192GB / server.
Do you have 100Gbit of traffic or 100Gbit interfaces?
Either way, you’re gonna build yourself a cluster with a packet broker in front of it. Arista works well, other people use different brands, depending on your needs and your budget.
Give those tuning guides I wrote with Suricata developers a read, while on it, they apply to Zeek as well. Of course Suricata can process way more traffic per core, than Zeek, because the processing it does is way simpler.