Okay so, I didn't like the idea of doing a pursuit so I found a much faster, and easier, way to get this achievement (in my opinion! You wanna do a pursuit more power to you :D).
I have a recording of all the steps below. If you want a text explain then see below as well but the video makes everything much more detailed:
PREREQUISITE: You must have a Spy character. You get one from liberating the city of Westminster and more can be found near MI6 which is right above the Vauxhall travel point in the very right edge of Nine Elms.https://gameclips.io/Karma%20Arsonist/d3c2141b-bd46-4757-858...
1. Go to the Bank travel point which is in the City of London and if you zoom the map out all the way and look directly under the ND of London as you are zooming in you will see the Bank travel by a clothing store.
2. Go up the fast travel stairs and immediately turn left, you will see the bank in front of you. Go in the the front door and use the security cams in the next room to tag all 5 Albion security personnel in the next room - this is to ensure they are close enough together but the range on the watch is really large so should be no problem.
3. Hop the counter to the direct right or left of the scanner... do NOT walk through the scanner please. Move forward till the 2 guards on the ground floor are pretty close to you without getting spotted (they should just stand by the stairs leading up), stay behind cover while crouch moving toward them, and when all 5 are close ish to you hit the watch button and achievement is yours.
4. Walk back out the same way you came in and move on to the next one.