It does get tricky maneuvering around smaller and confined maps, if you aren't confident about rambo-ing , or maybe you're not comfortable kiting around in a small area or just don't know your enviroment , u can always go around a limited area "near" your team.
For example in offices, if your team is holing up at the 2nd floor, the one with many weldable doors , the floor right before the roof. You can go down around the 1st floor and go back up to your team and repeat.
Somewhat like westlondon, if your team is holing up in one of the tunnels, go around the whole map, making a pitstop in where they are holing up checking if they need help etc.
Instead of going somewhere completely off, where if you come across an "oh sh!t" situation, you can always call for help or fall back. In most cases, the very least u can expect in pub games, is seeing a medic coming down to help ya.
I also prefer zerks who do this, because in some instances where the peeps holing up get into sh!t, we can always expect the zerker to come in and help out. Unlike some zerks who go out all in their own and either die alone or be the last one alive facing xxx number of zeds on xxx wave.