This is just a simple tip, if you want to get your Swarm or K9 fast and very easily run Vsat, EMP, then either Swarm or K9. Because when you get your Vsat, after only a little bit more points you get your EMP right away.
Now with the Vsat and EMP up you get a good amount of assist points piling up which adds to your score streak and then just go out and get about a few kills usually (3-5) and then you have your Swarm or K9. Not to mention you really do wanna be using a suppressor on your gun along with using Ghost and Hardline.
The Vsat gives away their position, then the EMP blinds them in way so it makes extremely easy to go out and get those kills.
This is not the only way to get Swarms or K9's but its a easy and fast way, once you get better you wont have to always use the Vsat or the EMP all the time. Alot of people play in party's and help each other out, but I play solo most of the time and have no problem owning, but its usually me doing the work for the whole team because I get put in shitty lobbies.
So hope this helps you guys out!