We still should try to find two cross pops in one week in one team. (afaik nobody reported two cross pops, am I right?)
Then we could create more hypotheses (and reject others).
Maybe always only one player in team receives cross training? (Without confirmed two pops we can't reject this hypothesis).
As far as I've seen, no, only one guy in the team seems to get the cross training, and in only one skill. But I think these are excellent points, and until we know for certain otherwise, we have to assume it's possible. At this point, we really don't know if cross training just effects one random skill, or if it has a "blanket" effect over all the skills of a player (spreading the 10% loss over all skills not trained).