I have made a Windows command line tool for the NHL 95 PC version that allows you to increase or decrease all players' or goalies' attributes, hopefully it will be useful for someone else too. For example, I find the pace of the game a bit too slow by default, so I can increase the players' speed attribute by 30 or something. The tool is described in more detail on its GitHub page where you can also download it.
The tool can also add a team to the database (by copying the first team's data), which you can use as a starting point if you want to try adding a team to the game. The added team will show up in some menus but trying to use it will crash the game. By debugging the crashes someone could possibly figure out what changes need to be made to really add teams. I tried starting it myself but I haven't done any DOS debugging before and it seemed it would just require too much time to be worth it.