Super Soccer Euro edition is a hack which changes the 16 teams, as well as the stats, as you see Serbia's. Even the player's stats are changed, to suit. You can play as the mighty Spain down to the low ranked Luxembourg.
When you complete Tournament mode, you will play a team which is tougher than Nintendo. Readme is in the zip.
Readme:
Patch to an American Region Super Soccer, and make sure that the ROM is headered before applying the patch.
Super Soccer (USA).sfc - NOINTRO
CRC32: 4FD164D8
MD5: 15BC713C9464C0E3243D1DBCF75C9BEE
SHA-1: 47F401CF0B5845E129B636D381233C23BA74CEF6
SHA-256: 694AD2B34AB808BD8A1AA9DDA359594CFD3A5FD9D95D4CF262CCAA0EB57EEF67