Sure the Bible says only Jesus save. But Jesus is alive and He will judge us in the end.
We can't know what will happen. I know that none will say I was wrong judged.
Many people before Jesus believed in their gods through their lives but Jesus when died these 3 days teached the deads and many believed him and saved. We don't know how this happened.
If you look at the Jewesh scripts before Jesus you will understand that all the other nations will be lost to Hell forever. But Jesus teached them also -although dead- and many of our anchestors saved.
Our only concern wil be how to save our souls and not how should other religions be judged by Jesus.
I totally agree that from our scripts seems there is no salvation for them.
But we can't tell Him what he will do and if so we should pray and peg to save them too. Remember that story about those slaves who worked all day and others for an hour and all took the same money from their master. When the first complained the master told that it isn't their business to tell him what to do and also told em that took what they agreed and not to look what agreement had with the other slaves.