Looking for firewall recommendation

I am sure you can write code that splits up the program and maybe even use a fake name so it registers differently on the display.
But how can the OS not know what an individual process consumes in RAM and CPU cycles?

I think some of the AV testing companies don't want to publicize that some of these anti-malware applications can consume upwards of 200MBs of RAM or more!

Why would an upfront and legitimate software company want to fool their customers with incorrect resource readings...if that ever came out to the public that company's reputation would be lost.