1) Of the first 3 rosters I've found, all 3 appear to be ensemble teams. Team Canada is composed of players from 9 different universities (
Canada Roster Announcement). Australia has a mix of 5 guys who play in Australia & 7 who play in the USA like Nebraska's Jack McVeigh (
Australia Roster Announcement). Trying to use google translate on the Germany national team website is a little messy, but I think it looks like a collection of university kids & recent grads too.
2) Haarms is not allowed the extra practice time. Like stated above, he's limited like any player at a school not going on a trip (2 hrs of organized practice a week, I think).