I sorta know some of the issues behind this since I used to help manage a CS:GO Zombie Escape server.
Depending on how old the box is, the choke can go up. If I recall, HG has upgraded its hardware in a while. Usually if more clients are connected to the server, the more choke it will get.
There are also settings for sv_ commands to decrease the choke of a server too. I forgot the commands off the top of my head.
If HG is still running Linux, they should consider switching to Windows because it will give the servers a better performance boost. Valve has still not fix the Linux issue in CS:GO from what I heard.
If anything right now, HG probably needs new hardware. Valve updating CS:GO seems to be making servers with older hardware more obsolete. New hitboxes from last year was one of the updates that really took a shit on a lot of servers.