Nadya,
I don't think outside help for the teams is allowed. If it were it would make the whole idea of a team competition absent from the contest. If you think about it, the Boston Redsocks don't allow nonplayers to jump in and hit for someone. A team is a team and those not on the team are not on the team. In my opinion, one team getting outside help while the others don't is not fair to the teams that don't get the help.
If someone wants to cheer for a team go ahead, but I don't think that actually doing assistive work for the team is fair.