we do training in order to use up extra condition while waiting for next match which would otherwise be wasted. training would help players gain skill points which will help improve the players. but there is also risk of getting injuries during training. so it is your choice whether to do training or not. for stretching, as mentioned above, it's not like actual match. when i first started playing, i also thought same as you. i did stretching for my players a few minutes before every match that i managed to watch. but it is not actually correct thinking.