I too am all for sharing best practices. I just disagree with some of those practices. Using a mixed bag of a particular product from a variety of vendors sounds great from a management perspective. It seems obvious that one might catch something that another misses. Having a variety of security products watching a network is like how a variety of COVID vaccinations can be better than repeating the same vaccine each time. But more vendors means a greater variety of associated traffic. You end up poking a hole in one firewall so that someone can manage some other firewall. Your IDS sees, and gets used to seeing, all sorts of strange management traffic. Your engineers become complacent, opening up holes upon request by anyone with the correct phone number. There is something to be said for a single strong firewall system from a single vendor. Then you have a single reporting/monitoring system with no shirking of responsibility. That one wall is manned/watched/managed as everyone's first priority. One very tall wall rather than a series of shorter ones.
The practice I would promote, but which is rarely ever used outside of defense and/or the biggest companies, is having separate networks for the really important stuff. Why is client data is traveling along the same network as employees streaming netflix? Have one network for general office junk and another physically-distinct network for client data. Why is the office birthday party announcement landing in the same inbox as an email from a "client" requesting a wire transfer? If separating these means some employees have to run two email inboxes or have two computers at their desk, so be it. But doing that costs money. Subscribing to a 3rd or 4th firewall vendor is cheap.
The practice I would promote, but which is rarely ever used outside of defense and/or the biggest companies, is having separate networks for the really important stuff. Why is client data is traveling along the same network as employees streaming netflix? Have one network for general office junk and another physically-distinct network for client data. Why is the office birthday party announcement landing in the same inbox as an email from a "client" requesting a wire transfer? If separating these means some employees have to run two email inboxes or have two computers at their desk, so be it. But doing that costs money. Subscribing to a 3rd or 4th firewall vendor is cheap.