You can also say "يسلط الضوء على" instead of "يلقي الضوء على" I'm not quite sure about the etymology of the phrase, but it is used in Arabic very often and is comprehensible. And yes, the second translation is correct. However, if it's at the beginning of the sentence, it should be "مشجعو كرة القدم المتشددون"

يلقي مزيدا من الضوء على=Shed more light on This phrase we use in Arabic language in writing, TV news, etc. It's a direct translation. مشجعي كرة القدم المتشددين=hardcore football fans. المتشددين=hardcore (never heard anyone uses المتشددين in Arabic as hardcore it's more like racist/fanatic. We don't say hardcore football fans, maybe we say المتحمسيين=Excited. Hope I helped :)

Hardcore = متعصبين

Few Examples for you: أعنف مشجعي كرة القدم على الاطلاق The most violent football fans ever. جنون مشجعي كرة القدم The craziness of football fans. Or مشجعي كرة القدم المجانين The crazy football fans. Please ask if you need to know more or if you need me to break down for you the translation word by word :)

يلقي مزيدا من الضوء : Throw more light on To throw : يلقي . To send : يرسل . مشجعي كرة القدم المتعصبين التعصب : Fanaticism has a negative meaning, but this word also used for enthusiasm and loyalty.