I think that more people join with bots because when they are staying all the time in the server until 4 people is online so there is 4 bots when there is no one in the server like
1 real player - 3 bots
2 real players-2 bots
3 real players-1 bot
4 real players-no bots
and the bots weapon are:
Snife-Intervention & Karambit
Snipe-Intervention
Knife-Karambit