It is too bad that these girls got hurt, I hope none seriously. Are you referring to NC or SC? I have my personal observations. If you want to prove me wrong, than you put together the STATS! From your comments you obviously are not playing at a high level or in a professionally run training environment it the girls are just showing up and playing.
To frame this discussion, it does not even involve those who do not have ECNL/HS conflict. If you don't have an ECNL player then you have no way of knowing what the commitments are. If you were in ECNL you would know that the commitment that you sign in June is for a full year of, yes this is correct, of 13 months. Teams are picked in June because that is the established time, but ECNL will play through the following July. Regular club is completed in December. I would be careful about surmising because it would be a mistake for you to do so.