Both does the same, it uses a player's offset. Though, there is a difference about cs_set_user_team(), it set the team + send ClientUserInfoChanged + send TeamInfo message + pass the team name by reference.
In CC4::Use(), there is a check with the team offset to make sure you are in the CT team. So, all you need here is to set the offset with the CT team value (2), as pre, and restore as post. It does the trick. You don't need all the stuffs that does the cstrike native, that's why using the offset is enough.