I am a property manager (landlord).

IMO, if the person seeking the sublet doesn't screen YOU (written application and asks serious questions) and require that YOU pay a partial security deposit, they're shady.

There are people who bounce from sublet to sublet because they are too unstable to commit to anything and/or cannot qualify for a lease of their own. Professional subletters. Always looking for reduced rent and no security deposit.

Treat it as if you are looking for a non-temporary place to live, and you'll avoid a lot of the bullshit problems later on.