couple of things. not sure how long you have played (ie how back editions), but Cards are what has historically stopped 2 turn TD teams with a higher TV (3rd edition talking here)
Arguing the call. Straight out of 3rd ed. they removed it after 3rd. I like it back. As to the teams it hurts......undead/necro. without a coach you cant regen (at least that way in 3rd. Havent read the new book enough to see if they added that back in.
I would not expect a change to the teams (human catchers, weaping blades etc) in a league. Only the league rules.