I know how frustrating it can be. Please stay the course and continue the good work.
However, with consistency and the enthusiasm of a few keen folks, it can be a tide that will turn for the better.
After all, we only need to set the standards and others will follow.
I understand that not every one is a "true" team player.
Working on drills with accepting and dedicated team players should be not include such players.
Most of these simply do the bare minimum to support fellow team mates.
It is important to identify these players and obviously ensure they are left to their own devices, as in some cases they can be of great use as either cannon fodder, agitators or "agents provocateur" for the OP FOR.
They are "kill oriented" and see the score they achieve as the be all and end all, rather than an incidental outcome of their commitment to team play.
Trust me it works. It happened in the past and is happening now.
You find that if the team play is exceptional and effective, even these soloist join in, as they really have no choice.