Earlier quoted context omitted.
This isn't how cmd+tab works on a Mac. Do you mean alt+tab in Windows?
I don't really treat cmd+tab and cmd+` very differently, sorry. On my OS, both work: I can alt-` to cycle through windows of same application and alt+tab to cycle through each individual window (grouped by application); maybe that's given me the habit of treating alt+` merely as a filter on alt+tab. Oh! This is perhaps also why I get annoyed by cmd+tab on Macs!!
Which wm on which os do you use? gnome kde or something else?